Jeremy Corbyn has endorsed a plan to force a second EU referendum as he bowed to pressure from Labour party members and MPs.

Mr Corbyn wants the Government to give MPs the final say next week on a second referendum. If a majority back a referendum, Parliament could force Theresa May to hold a new in/out public vote that could lead to Brexit being reversed.

Supporters of the so-called “People’s Vote” were jubilant tonight, describing Labour’s new policy as a “momentous” move that brought a referendum a “massive” step closer.

It came after Mrs May warned MPs that a fresh referendum would “damage social cohesion” because it would “undermine faith in democracy”.

On Monday the Prime Minister outlined her Plan B for securing Parliament’s backing for a Brexit deal, which is centred on renegotiating the Northern Irish backstop with Brussels.

However, The Telegraph has been told that Oliver Robbins, Mrs May’s chief Brexit negotiator, privately undermined the idea even before she could announce it. He texted Philip Hammond, the Chancellor, during a Cabinet conference call on Sunday and allegedly said Brussels would not reopen the EU Withdrawal Agreement to renegotiate the backstop.

Separately, Amber Rudd, the Work and Pensions Secretary, warned Mrs May that up to 40 ministers could quit so they could support backbench plans to take a no-deal Brexit “off the table”. At least four other Cabinet ministers share her concerns and are understood to have issued similarly stark warnings to the Prime Minister as part of a push for a free vote on the issue next week.