The Starm-troopers! Keir gathers Labour MPs - all 411 of them - after they arrive for their first day in Westminster following party's huge landslide election win

Sir Keir Starmer gathered all 411 Labour MPs in Westminster tonight as he displayed the full size of his general election win.

The Prime Minister held the first meeting of the Parliamentary Labour Party (PLP) since last Thursday's vote in Church House - a stone's throw away from the Houses of Parliament.

It was suggested Sir Keir had chosen the venue as committee rooms in the House of Commons - where PLP meetings are traditionally held - were not big enough.

But, despite the celebratory mood among Labour MPs, the PM is understood to issued a warning that voters had only placed their trust in the party 'for now'.

'They're not converts,' Sir Keir was said to have told his MPs of the 9.7 million Britons who supported Labour last week.

Sir Keir Starmer gathered all 411 Labour MPs in Westminster tonight as he displayed the full size of his general election win

Sir Keir Starmer gathered all 411 Labour MPs in Westminster tonight as he displayed the full size of his general election win

Sir Keir posed for a 'selfie' with Brent East MP Dawn Butler as he held the first meeting of the Parliamentary Labour Party (PLP) since last Thursday's vote in Church House

Sir Keir posed for a 'selfie' with Brent East MP Dawn Butler as he held the first meeting of the Parliamentary Labour Party (PLP) since last Thursday's vote in Church House

Despite the celebratory mood among Labour MPs, the PM is understood to issued a warning that voters had only placed their trust in the party 'for now'

Despite the celebratory mood among Labour MPs, the PM is understood to issued a warning that voters had only placed their trust in the party 'for now'

It is understood the PM told the PLP meeting in his remarks: 'Election victories do not fall from the sky.

'They are hard won and hard fought for and this one could only have been won by a changed Labour party.

'We campaigned as a changed Labour party – and we must govern as a changed Labour Party. People have placed their trust in us for now, but they're not converts.

'We have to return politics to public service, to show to the British people that politics can be a force for good.

'We have a mandate for change, a mandate for renewal.'

As she left the PLP meeting, Bradford West MP Naz Shah said the central message of Sir Keir's speech to his MPs had been 'the grown-ups are back in charge'.

She said: 'It's not a playground, this is running the country and hitting the ground running.'

Sir Keir attended the PLP meeting having earlier completed his triumphal tour of the UK in the wake of Labour's landslide election win.

After meeting with Scottish First Minister John Swinney in Edinburgh last night, the PM met with devolved leaders in Belfast and Cardiff today. 

Speaking to reporters in the Welsh capital, the PM admitted he was 'concerned' about those areas where Labour was not able to secure votes last week.

Thursday's election saw a strong performance by a number of independent candidates who stood on a pro-Gaza platform in the wake of the Middle East conflict. 

Sir Keir was asked if he accepted there is a problem between Labour and British Muslims, following a drop in vote share in areas with a high Muslim population.

He replied: 'Very many people voted Labour in that general election who've never voted Labour before.

'We now hold seats in parts of the country that have never had a Labour MP, so this is an incredibly strong mandate.

'Of course, wherever we weren't able to secure votes, I'm concerned about that.'

He added that where his party did not secure the votes it would work to 'address that'.