British Prime Minister Boris Johnson challenged his Labour rival Jeremy Corbyn to vote in favour of an early election on October 15 later on Wednesday.
In a heated parliamentary debate, Johnson said that if Corbyn voted in favour of a draft law against the government's Brexit strategy then he should also support an election to "allow the people of this country to have their view".
The development comes a day after Johnson lost his working parliamentary majority ahead of a crucial Brexit vote after Conservative MP Phillip Lee defected to the pro-EU Liberal Democrats.
"The Liberal Democrats are delighted to announce that Bracknell MP Phillip Lee has joined the party," the Lib Dems said in a statement.
