A group of influential German politicians and business leaders including the woman primed to take over from Angela Merkel as chancellor have urged Britain to stay in the EU as Brexit looms.

Annegret Kramp-Karrenbauer, who became leader of the centre-right Christian Democratic Union last month, joined more than two dozen political, business and cultural figures in penning an open letter to the Times, arguing “from the bottom of our hearts” that Britain should not leave the bloc.

“Britain has become part of who we are as Europeans,” the letter read. “We would miss Britain as part of the European Union, especially in these troubled times. Therefore Britons should know: from the bottom of our hearts, we want them to stay.”

The letter said they respected the choice of the British people to leave, but if the UK decided to stay, “our door will always remain open”.

Nodding to the two countries’ shared history, the group said Britain “did not give up on us” after the second world war and welcomed Germany back into the European community. Germans “have not forgotten and we are grateful”, they wrote.

“Should Britain wish to leave the European Union for good, it will always have friends in Germany and Europe,” they said. “But Britons should equally know that we believe that no choice is irreversible.”

The German leaders went on to say: “We would miss the legendary British black humour and going to the pub after work hours to drink an ale. We would miss tea with milk and driving on the left-hand side of the road. And we would miss seeing the panto at Christmas.

“But more than anything else, we would miss the British people – our friends across the Channel.”

Kramp-Karrenbauer was the most high-profile signatory of the letter, but she was joined by politicians including Andrea Nahles, the leader of the Social Democratic party, the Greens co-leaders and the head of the German parliament’s foreign affairs committee.

The signatories also included the president of the Federation of German Industries and senior executives at Daimler and Airbus, as well as sporting and cultural figures such as the former German footballer Jens Lehmann and the singer Campino.

The plea came as some in Berlin predicted disastrous consequences if no Brexit deal was reached and signalled openness to the possibility of Britain staying in the EU.

On Thursday, the German parliament passed a Brexit transition law, which would only take effect if the planned transition period until the end of 2020 were initiated. The foreign minister, Heiko Maas, said the ball was in the UK’s court, adding that “the time for games is over”.

Expressing her regret that the House of Commons rejected Theresa May’s Brexit deal, Kramp-Karrenbauer said: “We will not block the path to Britain remaining in the EU. London must now put forward constructive proposals as to how to proceed.”