Priti Patel arriving at Downing Street before she resigned from the cabinet last night. She admitted failing to disclose full details of her contacts with Israeli politicians Carl Court/Getty Images

European Union leaders are preparing for the fall of Theresa May before the new year after the prime minister lost her second cabinet minister in a week.

Fears are growing in Brussels that the instability of Mrs May’s government raises the real prospect of a change of leadership or elections leading to a Labour victory.

One European leader told The Times that officials were planning for both scenarios. “There is the great difficulty of the leadership in Great Britain, which is more and more fragile,” the leader said. “Britain is very weak and the weakness of Theresa May makes [Brexit] negotiations very difficult.”

All options are under consideration in Brussels, including a “no deal” disorderly exit by Britain from the EU or a reversal of…