Further integration among eurozone countries should not restrict trade in the European Union’s single market, the bloc’s finance ministers agreed yesterday, an important pledge for Britain as it prepares to vote on whether to remain in the EU.

The ministers met in Luxembourg to go over a report on how the 19 countries sharing the euro should integrate in the next 10 years. Ministers from the nine countries not using the euro took part to point out their concerns about where the euro zone is heading.

“The key is a legislative constraint, and a political one, that we all agree that we must ensure that the integrity of the EU single market is preserved,” Luxembourg Finance Minister Pierre Gramegna, who chaired the talks, told a news conference.

As the eurozone plans tighter links for its economies and financial services, Britain wants to make sure that it is not left out of future discussions, especially on decisions that may affect the City’s financial industry and British interests.

“The discussion is open to find out if there are harms to non-eurozone member states,” Mr Gramegna said.

Ministers agreed to be more open about decisions taken in the eurozone and their consequences to non-eurozone countries. They will also try to limit any negative consequences for countries not sharing the euro, Mr Gramegna said.

British Chancellor of the Exchequer George Osborne left without making any comment. Before the meeting, he had tweeted that the debate would be about the “long term relationship between euro ins/outs”.

European Central Bank member Ignazio Visco said after the meeting that “the cooperation with Britain was progressing”.

“Osborne insisted that progress in the integration of the eurozone should not affect the internal market,” he told reporters.

British Prime Minister David Cameron has pledged to renegotiate ties with the EU before a referendum in 2017 on whether Britain will remain a member.