The UK is secretly considering whether to enter a customs union with the EU after Brexit, according to a report from the Financial Times — which could help maintain trade with Europe but damage the UK's global deal-making and enrage Brexiteers.

The government is currently looking into the possibility, three unnamed officials told the paper, which could come into effect after a two-year transition period following Brexit in March 2019.

A Customs Union would allow free trade among members (i.e. the UK and the EU), and a common external tariff on trade with non-members (i.e. the rest of the world). It offers some advantages, including its relative simplicity and the fact it could help to deal with the thorny issue of the Irish border.

But it could also make it more difficult to strike trade deals outside of the European Union. Theresa May has previously insisted the UK would leave the Customs Union, and to do otherwise would likely infuriate the pro-Brexit wing of the Conservative Party — at a time when May's leadership is already in serious question.

Pro-European politicians, meanwhile, have hailed the news as a positive step. "Customs union deal is really important for Yorkshire manufacturers," Yvette Cooper MP, Chair of the Home Affairs Select Committee wrote on Twitter. "I hope this [Financial Times] story is right - up til now Govt has refused to even do an impact assessment on customs union."