A return to the EU could leave Britain paying roughly £5 billion more each year, according to internal estimates cited by Bloomberg, as old opt-outs from the pre-Brexit era appear unlikely to survive.

British officials have informally sounded out EU counterparts about what re-entry might look like. The message from Brussels, according to the report, was that the UK should not expect to recover Margaret Thatcher’s budget rebate and that freedom of movement would be non-negotiable.

The figures are still only estimates, not agreed terms. But they underline how different any future accession deal would be from the membership Britain had before Brexit.