The next general election will not be fought over whether Britain should rejoin the European Union, Sir Keir Starmer's chief Brexit negotiator has pledged.Nick Thomas-Symonds, Minister for the Constitution and European Union Relations, said he was firmly fixed on developing what he called a "post-Brexit landscape" with the EU.This did not involve breaching any of Labour's three red lines on Brexit in the party's 2024 election manifesto: no retur…