Britain will not be the only “prisoner” wanting to leave the European Union if it is turned into a jail, Jeremy Hunt has warned.

The Foreign Secretary took aim at Brussels’ handling of the Brexit negotiations, telling the EU to “never ever mistake British politeness for British weakness” in a punchy speech to the Conservative Party conference.

He said the EU seemed to want to “punish” a member for leaving, likening their tactics to the Soviet Union, and told delegates in Birmingham: “The lesson from history is clear: if you turn the EU club into a prison, the desire to get out of it won’t diminish it will grow and we won’t be the only prisoner that will want to escape.

“If you reject the hand of friendship offered by our Prime Minister, you turn your back on the partnership that has given Europe more security, more freedom, more prosperity, more opportunities than ever before in history – and a setback for the EU will become a wholly avoidable tragedy for Europe.”

Jeremy Hunt at the Conservative Party annual conference
Jeremy Hunt at the Conservative Party annual conference (Stefan Rousseau/PA)

Mr Hunt echoed former prime minister Margaret Thatcher as he told the conference: “Of course we understand that the EU wants to, it needs to, protect itself.

“But if the only way to deal with the UK leaving is to try to force its break-up, as someone much more distinguished than me once said, the answer is, ‘No, No, No’.”

And he added: “So as your friends of many years we say very simply this: Brexit is not about whether you succeed or we succeed – Europe prospers when we both succeed and it’s time to change your approach.”

Mr Hunt received a standing ovation following his well-received speech, which fuelled speculation over a leadership bid.

The Cabinet minister called on his colleagues and party members to “come together” and “show the doubters, show the sceptics, show the world the true potential of this remarkable nation”.

Mr Hunt, who became foreign secretary in July, also joked about his first moments in the role, describing how he walked up the Grand Staircase in the Foreign Office and looking at the pictures of his predecessors on the wall.

“One of the more recent ones seemed to have forgotten to comb his blonde hair”, he quipped.

And delegates applauded and laughed as he told them how meeting world leaders abroad was “peanuts” compared to the “diplomacy you need at home when you call your Chinese wife Japanese”.

Mr Hunt also repeated his calls for the release of imprisoned charity worker Nazanin Zaghari-Ratcliffe, saying he also has a four-year-old daughter and “can’t imagine what that family’s going through”.

In a message to the Iranian government, he said: “So whatever disagreements, for the sake of our common humanity it’s time to let her and others come home.”

Responding to a tweet highlighting Mr Hunt’s comparison of the EU to the Soviet Union, Latvia’s ambassador to the UK Baiba Braze said on Twitter: “Soviets killed, deported, exiled and imprisoned 100 thousands of Latvia’s inhabitants after the illegal occupation in 1940, and ruined lives of three generations, while the EU has brought prosperity, equality, growth, respect.”