The European Union is to show its determination to make no concessions to the UK on Brexit terms by telling Switzerland it will lose access to the single market if it goes ahead with plans to impose controls on the free movement of EU citizens.

The Swiss-EU talks, under way for two years but now needing a solution possibly within weeks, throws up the exact same issues that will be raised in the UK's exit talks - the degree to which the UK must accept free movement of the EU's citizens as a price for access to the single market.

The Swiss are desperate to strike a deal in order to give its politicians time to pass the necessary laws to meet a February 2017 deadline imposed by a legally binding referendum in 2014.

The former president of the FDP-Liberal Radicals, Philipp Müller, on Sunday said the Brexit threat should serve as a warning to the Swiss, amid suggestions in Brussels the prospect of UK-EU exit talks meant there was less willingness to give ground on freedom of movement.