BRITAIN would stay in the European Union if a Labour government failed to secure a deal with Brussels, Sir Keir Starmer has suggested.

The Shadow Brexit Secretary said MPs would be given a veto over any Brexit deal secured by a Labour government, potentially sending Jeremy Corbyn back to Brussels to try again and delaying the process of leaving the EU.

Sir Keir said it was vital to get the "best deal we can" and the UK Government had to be prepared to return to talks if what was on the table was rejected by Parliament.

Setting out Labour's approach to Brexit, Sir Keir said the party would unilaterally guarantee the rights of EU citizens in the UK, without waiting for a reciprocal commitment on the status of Britons on the continent.

And he condemned Theresa May's "rigid" and "reckless" decision to rule out membership of the single market and customs union as part of any Brexit deal.

Challenged that Labour's position on a binding vote for Parliament could mean not leaving the EU at all, Sir Keir said: "We have to get the best deal we can.

"We are talking about the tail end of 2018, we would have a vote, we would go back to the negotiating table. That is the position that we want to adopt on a meaningful vote."

Criticising Mrs May's "out, out, out" approach on issues such as the single market, customs union and European Court of Justice, Sir Keir said: "She may be clear but she is rigid and she is reckless."

The Prime Minister has said the UK "cannot possibly" remain part of the single market as it would mean "not leaving the EU at all", while leaders across the bloc have warned that Britain cannot enjoy the benefits without agreeing to the rules, such as freedom of movement.

But saying that options should be kept open, Sir Keir told BBC Radio 4's Today programme: "We want businesses to trade as successfully in the future as they have done in the past. That is not a wish list, it is an absolute imperative in these negotiations.

"We accept that unchanged single market membership is not a viable option, but we would want to leave the options on the table, to discuss with our European colleagues what the appetite is for change and revision and reform of some of the single market rules.

"I'm not pretending that's going to be easy."

Under Labour's plans Theresa May's flagship Bill to transfer relevant EU laws to Britain would be replaced with legislation that would protect employment and consumer rights as well as environmental protections when powers are repatriated.

Labour's push to clarify its stance on the EU negotiations came as campaigners drew up a hit-list of Brexit-backing MPs they will try to oust at the June 8 General Election by flooding their seats with activists.

Key Leave supporters will be targeted in 20 constituencies, while support will be given to 20 MPs who have spoken out against a hard exit from the EU since the referendum.

Among the seats that pro-European groups Open Britain, European Movement and Britain For Europe plan to attack during the campaign are those of Tory former Cabinet minister Iain Duncan Smith and Labour's Kate Hoey.

It will also draw on its database of 600,000 supporters to support Labour's Mary Creagh, Conservative Neil Carmichael and Green MP Caroline Lucas.