European Union fishing fleets must be given wide-ranging access to British coastal waters as the price of agreeing an all-UK Brexit divorce deal, the Telegraph can reveal.

Senior EU diplomats have warned that any plan to grant the UK a temporary customs union to solve the Irish backstop problem must come with cast-iron guarantees that EU boats will be free to fish in UK waters.

The EU demands threaten to re-open a fierce row inside the Tory party over the potential size of the Brexit dividend for coastal and fishing communities.

Fishermen warned Mrs May that she must not “squander” the chance to claw back valuable quotas for British fleets, while MPs representing fishing communities said extending the current arrangements would be “totally unacceptable”.

It came as Downing Street signalled it was desperate to clinch a Brexit deal before the end of November, with a timetable circulating in Whitehall suggesting the outlines of a withdrawal agreement text may be agreed by the Cabinet on Tuesday next week.

Dominic Raab, the Brexit Secretary, would then travel to Brussels to agree the text with the EU, before Mrs May presented the plan to Parliament on Wednesday.