Britain's exit from the EU could be blocked, Tony Blair has said, as he ruled out a return to frontline politics because there is “too much hostility” towards him.

The former Labour prime minister said he had been accused of “treason” for suggesting that Britain keep its “options open” over Brexit.

But he insisted that voters had a right to decide they want to stay in the EU after “scrutinising” Theresa May’s final deal with European leaders.