Jeremy Corbyn has remained tight-lipped about the contents of his party’s General Election manifesto but has insisted migration into Britain is vital to maintain the economy.

Immigration re-emerged as a key election battleground and was said to have been a “difficult” issue for Labour ahead of a meeting on Saturday to hammer out the final details of the manifesto, which will be unveiled on Thursday.

Mr Corbyn refused to confirm whether free movement of people would end if the UK leaves the EU under a Labour Government, while shadow health secretary Jon Ashworth refused to say whether immigration would increase or decrease.

Mr Corbyn told The Andrew Marr Show on BBC One: “A lot of European Union nationals have made their homes in this country and made a massive contribution to our society.

“A lot of British people live in different parts of the European Union.

“And many of those families have been through unbelievable levels of stress so they absolutely must have the right to remain and be able to bring their families here.”

Mr Corbyn added there are “huge economic demands” in the UK with the need for nurses and doctors.

“We cannot exist in isolation, therefore there has to be migration into Britain in order to maintain our economy and our services,” he said.

“And that will be reflected in the policy which you will see on Thursday.”

Further pressed on whether free movement will end when the UK leaves the EU, Mr Corbyn said: “There will be a great deal of movement.”

Elsewhere, shadow health secretary Jon Ashworth told Sky News’ Sophy Ridge On Sunday: “We want a balanced approach to immigration and what that means for the NHS is if a hospital trust thinks that a surgeon or a nurse or a midwife is qualified enough to come to our country to care for our sick and our elderly and offers them that opportunity, then they should be allowed to come to our country to care for our sick and our elderly.”

Pushed further, Mr Ashworth said: “A Labour Government is not going to set an arbitrary target – that the Government are – because they’re not credible, they’re never delivered, they’ve never been delivered for 10 years under a Tory Government.”

Meanwhile, Mr Corbyn was repeatedly asked to give his own personal view on whether the UK should leave the EU.

He told The Andrew Marr Show: “We’re going to put that choice to the British people and they will make that decision.

“We’ll negotiate within three months a credible, sensible option of Leave and put that alongside Remain in a referendum.”

Shadow chancellor John McDonnell tweeted: “We just saw a Prime Minister on Marr and his name is Jeremy Corbyn.

“Displaying the confident, serious and knowledgeable leadership this country needs.”