Sir Keir Starmer teed up a new Brexit battle as he confirmed he is prepared to align the UK even more closely with the EU, including the single market, if it is in the UK's 'national interest'.

In some of his strongest comments yet about Britain's post-referendum relationship with Brussels under Labour the Prime Minister said he would look at returning to a system scrapped when the UK left in 2019.

However such a move would trigger a major political row at a time when migrant numbers are already near an all-time high.

It would also see him renege on yet another 2024 election manifesto pledge, having pledged 'no return' to the system.   

The single market is built on the premise of free movement of goods, services, capital and people, with the latter one of the key drivers behind the Leave campaign a decade ago.

Speaking to the BBC Sir Keir insisted there would be no return to free movement beyond a youth mobility scheme allowing thousands of EU and UK citizens aged under 35  to work and travel freely. 

But the EU is certain to make wider free movement of people part of any negotiations around single market access.

Sir Keir told the BBC's Sunday With Laura Kuenssberg: 'I think we should get closer, and if it's in our national interest to have even closer alignment with the single market, then we should consider that, we should go that far.

'We're already aligning on energy, reconnecting to energy in Europe on emissions, but I think the single market further alignment, as I say, if it's in our interest to do so, we should take that step.'

Conservative shadow foreign secretary Dame Priti Patel said: 'Labour's Brexit betrayal is becoming clearer by the day.

'In a desperate bid to appease his backbenchers, Keir Starmer is pursuing alignment with the Single Market - surrendering our freedom to cut regulation and strike our own trade deals.'

In some of his strongest comments yet about Britain's post-Brexit relationship with Brussels under Labour the Prime Minister said he would look at rules governing border checks

Speaking to the BBC Sir Keir insisted there would be no return to free movement beyond a youth mobility scheme allowing thousands of EU and UK citizens aged under 35 to work and travel freely

Sir Keir did appear to pour cold water on suggestions the UK should re-join a customs union with the bloc after his Health Secretary Wes Streeting said the arrangement had 'enormous economic benefits'. 

Asked whether he would be willing to revisit freedom of movement, allowing EU citizens with no limit to come to the UK, he said: 'No, but we are looking at a youth mobility scheme which will be for young people to travel, to work, to enjoy themselves in different European countries, to have that experience.'