Sir Keir Starmer has publicly acknowledged “where some on the Left went wrong” on immigration, writing in the Telegraph that his party needs to tackle “every aspect of the problem”.

He said that Labour was being forced to counter the “rise of the populist Right”, noting that the increasing popularity of Reform UK posed a challenge for both the Conservatives and the left.

The prime minister is expected to announce plans for a compulsory UK-wide digital ID scheme in a speech later on Friday, as part of the Labour Party’s push to address illegal immigration.

His government has been under increasing pressure to tackle the issue, after small boat migrant crossings surpassed 50,000 in August.

“The first essential part in doing that [challenging the populist Right] is in recognising where some on the Left went wrong on the issue of immigration,” Sir Keir wrote in the Telegraph piece.

“There is no doubt that for years, Left-wing parties, including my own, did shy away from people’s concerns around illegal immigration. It has been too easy for people to enter the country, work in the shadow economy and remain illegally.”

Ahead of his speech, Sir Keir wrote that Labour “must make and win the case for patriotic national renewal, based on enduring British values”, calling on “fair-minded Britons” to reject Reform’s “toxic” solution.

His piece also detailed the perils of “poisonous” online debate, and warned of a “coming struggle, a defining struggle, a violent struggle” for the nation.

Addressing the wave of protests that took place outside UK asylum hotels over the summer, the prime minister said his party would “reject the quick-fix solutions from those who want to divide” and instead focus on “restoring power to local communities”.

The government announced a £5bn funding boost for 339 “overlooked” communities on Thursday, with specific spending to be determined by those who “know their communities best”.

The announcement is part of Labour’s strategy to tackle the electoral threat posed to them by the rising popularity of Reform UK, and will include the £1.5bn pledged to 75 of the “most deprived” areas in the UK earlier this year.

Sir Keir is expected to defend his party’s approach to immigration in his speech, detailing the new digital ID scheme while laying blame for illegal immigration on 14 years of “Conservative government’s failure”.

He will be addressing the Global Progress Action Summit in London. Labour’s annual party conference opens in Liverpool this weekend.

Conservative leader Kemi Badenoch has characterised the announcement as a “desperate gimmick” to distract attention from the “leadership manoeuverings” of Greater Manchester Mayor Andy Burnham ahead of Labour’s annual conference next week.

Reform denounced the plan as a “cynical ploy to fool voters that something is being done about illegal immigration”.

The Liberal Democrats, who played a central role in blocking the previous Labour government’s ID cards, have said they “cannot support” a mandatory scheme.

This summer the UK and France agreed to a year-long “one in, one out” pilot scheme as part of the government’s strategy to deter small boat crossings.

Under the deal, the UK can immediately detain anyone who crosses the English Channel and agree with the French authorities to return the individual in a two-week time frame.

For each migrant the UK returns to France, another migrant with a strong case for asylum in the UK will come in return.

A tech start-up investor is taking a leading role in Reform UK’s efforts to access sensitive data in a bid to identify savings in one council controlled by the party, the BBC has learned.

Harriet Green, the founder of Basis Capital, is helping Reform UK’s Department of Government Efficiency (Doge) find ways to cut costs at West Northamptonshire Council.

She is an entrepreneur whose firm invests in businesses that provide services and work with, or compete against, local government.

Local councillors have raised concerns about whether it is appropriate for Green to access council data and questioned whether businesses backed by Basis would gain an unfair advantage over competitors.

Green declined to comment. Reform UK did not respond to requests for comment.

The BBC has been told Green is the only person Doge has put forward to access data at the council in Northamptonshire so far.

Senior council officers are vetting Green as they consider a proposal to allow her to analyse records of spending on items such as IT systems and hotels housing asylum seekers.

When Doge was launched after May’s local elections, Reform UK said a team of software engineers, data analysts and forensic auditors would “visit and analyse” spending at all of the councils controlled by the party to find “waste and inefficiencies”.

But the unit has been hampered by legal constraints and has not been able to access any council data so far.

Doge has only visited three of the councils controlled by Reform so far. It’s planning to visit a fourth, Lancashire County Council, in October.

Reform UK sources say they see the proposed data-sharing exercise and Green’s role in it in Northamptonshire as a potential model for gaining access to sensitive information at other councils.

Green’s company, Basis, launched last year and describes itself as an “early stage investor reimagining what governments can no longer deliver”.

Basis invests in companies such as Civic Marketplace, which is a public procurement platform designed to connect government agencies with service contractors.

In an interview with the Spectator this year, Green said Basis was a private fund set up to “invest in companies that are building where the state is failing”.

“A loftier way of putting that is we’re trying to outcompete the state,” said Green, a former intern at the Adam Smith Institute, a pro-free market think tank.

Councillor Daniel Lister, who leads Conservative opposition at the council, said Green’s role raised questions about potential conflict of interest given Basis’s stated mission and investments.

Lister said: “When a party unit opens the door to council data, it creates an inside track where firms built to outcompete the state will thrive.”

Jonathan Harris, the Liberal Democrat group leader, questioned what experience Green had in data handling and identifying savings at local authorities.

“There are questions not only about skill-sets but also about whether being involved in a Doge-type activity could provide some form of competitive advantage and access to information which others would not have,” Harris said.

“This would not be allowed under procurement rules for public bodies.”

The councillor said Doge and Green must be vetted by the council’s scrutiny committee if approval was granted.

Doge is led by Zia Yusuf, Reform UK’s head of policy and its former chairman, and was inspired by billionaire Elon Musk’s efforts to cut government costs in the US.

It was set up in June this year after Reform UK took control of 10 local authorities in May’s local elections.

“Our team will use cutting-edge technology and deliver real value for voters,” Yusuf said.

But progress has stalled over data access and instead, Reform UK councillors are trying to find savings without Doge.

In Kent, a cabinet member for local government efficiency has been created, and the county council’s Reform leader has claimed potential savings worth millions have been identified.

Lancashire is finding it tougher, with the Reform UK county council leader there telling the BBC cutting costs won’t be easy.

Councils across England face significant financial pressures after years of tight funding.

Yusuf’s Doge has come closest to accessing data in West Northamptonshire, where in July the cabinet “approved a mechanism to review information sharing arrangements that could lead to potential future opportunities for identifying savings and efficiencies at the authority”.

In a report, the council said its executive leadership team had met “Reform UK visitors” twice to discuss “potential opportunities to share data with third parties for the purpose of identifying efficiencies and potential savings”.

The report said by law, local authorities must not “promote or publish any material to affect public support for a political party”.

“As the Doge offer is from and associated with Reform UK, a political party, this prohibition and the public law principles alongside it are of particular impact,” the report said.

The council said it understood members of Yusuf’s Doge team were “not employed by Reform UK” and had offered their services at no charge.

Council sources say they are still working through the vetting process.

In the meantime, the party insists the unit’s work is ongoing, pointing to deputy leader Richard Tice’s recent announcement about local government pension schemes.

Yusuf has frequently complained about “waste” in local government and the way in which contracts for services are procured, alleging a lack of competition and corruption.

In her interview with the Spectator, Green was asked whether the political appetite for US President Donald Trump and Doge filled her with confidence.

Green said: “I think there’s a UK-way of doing things that we haven’t felt out yet.

“I don’t think it needs to be brash or kooky or partisan. Those things give you a litmus for something maybe being timely and it’s a good opportunity.”

She added: “I’m not convinced that anyone in the public sector is incentivised in a way that gets good outcomes for the work that they’re doing.”