Sir Keir Starmer said £550 million of investment to build new homes would enable more people to get on the housing ladder.

Schroders, Man Group and Resonance announced new impact investment funds on Tuesday which will go into housebuilding.

“We’ve said as a government we’re going to fix the foundations, rebuild our country, and expressly saying ‘now is the time to back us’,” he told the BBC.

“Companies and investors are coming in today saying ‘here’s half a billion pounds’. We want to raise that, by the way, I want that to be up over £1 billion before too long.”

The money would fund construction across the country because “too many people”, especially the young, “want to get on the housing ladder because they know that owning your own home is sort of base camp for their aspirations in life”.

“They haven’t had that for many years because the last government failed.

The prime minister again declined to rule out increasing employers’ national insurance contributions but insisted the Government would keep its manifesto promises.

He told the BBC: “We were very clear in the manifesto that we wouldn’t be increasing tax on working people and we expressly said that that was income tax, that was NICs etc.”

He added: “It wasn’t just the manifesto, we said it repeatedly in the campaign and we intend to keep the promises that we made in our manifesto.

“So I’m not going to reveal to you the details of the Budget, you know that that’s not possible at this stage.

“What I will say is where we made promises in our manifesto, we will be keeping those promises.”

The prime minister is asked if weight loss drugs could play a part in helping get people back to work.

He responded: “I think these drugs could be very important for our economy and for health.”

The prime minister said the investment summit on Tuesday was a huge success.

He said: “These are investors with a huge amount of capital to to invest, but can choose where they invested. We made the case that now is the time to invest in Britain, and yesterday we’re able to announce £63bn pounds of inward investment into Britian.

“But for viewers what that means is investment into projects that are secured jobs in every part of the country.”

The prime minister is now being interviewed outside Downing Street.

Speculation that Labour is considering raising employer national insurance tax contributions has been renewed after Rachel Reeves refused to rule out the measure yesterday.

The hike would bring the levy up from its current flat rate of 13.8 per cent, with experts predicting it could raise around £17bn a year.

She said: “We are going to need to sort of close that gap between what government is spending and bringing in through tax receipts. But we are going to be a government that sticks to our manifesto commitments,” meaning not raising taxes on working people.

A Treasury source has also previously indicated that it is the view of the government that the move would be considered as a tax on business, and not working people, saying: “The commitments in the manifesto were clear and about protecting the incomes of working people.”

The Institute for Fiscal Studies’ Paul Johnson has called this into question, saying the move would be a “straightforward breach” of the Labour manifesto. However he added that it’s unlikely the party would be unable to avoid doing this in some way.

Shadow work and pensions secretary Mel Stride said it would be “absurd” for Labour to hike national insurance for employers and claim it was not a breach of the party’s manifesto.

Speaking to Sky News, he said Labour has “boxed themselves in” by “claiming they were not going to be a party that was going to have to put up taxes”.

Sir Keir Starmer has welcomed the President of Cyprus to Downing Street, after the island played a central role in early efforts to get aid into war-torn Gaza.

Cypriot president Nikos Christodoulides made a whistlestop visit to No 10 before he heads to the United Nations in New York, where he hopes to open talks aimed at ending the decades-long ethnic divide on the island.

A UN buffer zone extends across Cyprus, dividing the Greek south from the north-eastern portion of the island, which is administered by an ethnically Turkish government only recognised by Turkey.

As the two sat for the media at the start of their meeting, the Prime Minister said: “It is my privilege to welcome you here and it is fantastic we have got this opportunity to discuss issues of mutual interest, a long and very important history between our two countries.

“Both at the country to country level, but also at the people to people level.

“We have a very proud community here and it gives great strength to us as a country.”

The Independent’s political editor David Maddox and Whitehall editor Kate Devlin were Scottish politics reporters at the height of Alex Salmond’s powers. David writes about the political giant he knew with memories from Kate.