Sir Keir Starmer has compared shifting Labour towards a softer stance on Brexit to hitting his head against a brick wall.

The shadow Brexit secretary said the party had “moved a long way” towards a more pro-Remain position but he admitted it had been a “frustrating” process.

Labour has been embroiled in a long-running debate over its Brexit strategy, with Sir Keir playing a major role in the shift towards supporting the prospect of a Final Say referendum.

However pro-EU MPs want the leadership to go further, including deputy leader Tom Watson, who urged party faithful to sign up to public calls for Labour to be the “party of Remain”.

More than 10,000 Labour members signed up within hours of the new declaration.

Put It To The People march: Best of The Independent’s pictures Show all 24 1 /24 Put It To The People march: Best of The Independent’s pictures Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent Put It To The People march: Best of The Independent’s pictures Put It To The People protest 23 March 2019 Angela Christofilou/The Independent Angela Christofilou/The Independent

Pressed on whether he had been “dragging” Jeremy Corbyn “incrementally to a more Remain stance”, Sir Keir told The Political Party podcast: “There’s an element of that.

“We have shifted and moved our position and that’s been hard work at times. Frustrating, as sometimes I’ve felt I should build a brick wall in my room to hit my head against so I don’t have to go outside too often to do it.

“Bringing the party to what I consider to be a better position has been a really important thing in the last two years.

“And we’ve moved a long way. We could go a bit further, but we’ve moved a long way.”

It comes as Labour slumped to fourth place in the polls with 18 per cent support, prompting calls for Mr Corbyn to shift towards explicit support for a fresh public vote.

Support free-thinking journalism and attend Independent events

Senior Labour sources have indicated that a statement on the “evolution” of the party’s thinking on Brexit can be expected within weeks.

A recent YouGov poll for The Times put Labour on its lowest level, matched only by Gordon Brown during the 2009 financial crisis.

The Tories were on 24 per cent, Brexit Party on 23 per cent and Liberal Democrats on 20 per cent.

Ilford North MP Wes Streeting said: “I just hope that Jeremy Corbyn is looking at these numbers and soberly reflecting on how he is going to lead our party out of this mess, or whether someone else would be better placed to do that.”