Tensions emerged over José Manuel Barroso’s future as European Commission president on Tuesday when Sweden, which will assume the European Union presidency next month, rejected calls to postpone his reappointment.

Fredrik Reinfeldt, Sweden’s prime minister, said a delay in confirming Mr Barroso would weaken the Commission at a critical moment, when it is trying amid a severe recession to defend the EU’s single market and push forward stricter rules on financial regulation.