Rejoining the EU will likely mean the UK paying Brussels more than ever before, accepting migrants from Europe and committing to join the euro.
A bid to reverse Brexit could also end up being blocked by a referendum in France, The i Paper has been told.
It comes as the shadow contest to be the next prime minister has put rejoining the EU firmly back on the agenda.
Wes Streeting said the UK should “one day” return to the EU and that Labour should put the prospect of doing so in its next election manifesto. Andy Burnham, another frontrunner in any future race to succeed Sir Keir Starmer, said there was a “long-term case” for rejoining but has stressed it would not be an immediate focus if he were to govern.
This week, the European Parliament’s President Roberta Metsola said the EU’s “door was open” to Britain. However, the cost to the UK of reversing Brexit is likely to be high, according to EU sources and experts.
