London: Britain could rejoin a reformed European Union within a generation, Theresa May’s de facto deputy prime minister has said, suggesting it would be “something for future parliaments to consider”.

In an interview with The Daily Telegraph, David Lidington, the Cabinet Office Minister who replaced Damian Green at the Prime Minister’s side in this month’s reshuffle, said it was impossible to predict what the EU would look like in “10 or 20 years’ time”. “It’s dangerous to say never,” he added.

Lidington, who campaigned for Remain during the EU referendum and is one of the government’s most prominent Europhiles, said he had not changed his views on Brexit but as a democrat it was his job to implement the will of the people. The former Europe minister now chairs several key Cabinet subcommittees on Brexit.

In his first interview since taking on the new role, he said it was possible Britain could join some form of customs union with the EU after Brexit. The government is committed to leaving the single market and the customs union, but Lidington said if there was “some different framework that we can arrive at in negotiations that will be mutually beneficial”, it could work to “everybody’s advantage”.

Earlier this week, Justine Greening, the former education secretary, suggested future generations of MPs could “undo” Brexit if it did not “work for them”. Emmanuel Macron, the French president, has said the UK could “find its place” in a “reformed and simplified EU” within a few years of leaving.

Asked whether Macron and Greening could be right, Lidington said it was a “red herring” to suggest Britain could rejoin the EU in its current form. However, he added: “We may be looking in a generation’s time at an EU that is configured differently from what it is today. The exact nature of the relationship between the United Kingdom and that future system, whatever it turns out to be, of European cooperation is something that future parliaments, future generations will have to consider.”

Yesterday May refused once again to say whether she would vote Leave if the EU referendum happened now. She said: “I would do what I did last time round which was sit down and look carefully at the issues.”

In an interview with a French television station, May was asked: “Do you feel European?” She replied “Yes”.

Since moving to the Cabinet Office, Lidington has spent most of his time taking charge of the fallout from the collapse of Carillion. He rejected Jeremy Corbyn’s suggestion that outsourcing had become a “racket” or that PFI contracts should be taken back under public sector control.