LONDON, Nov. 6 -- Prime Minister Boris Johnson warned Wednesday Britain faces a year-long "horror show" in 2020 if the impasse over Brexit is not resolved.

Johnson issued his warning from the steps of 10 Downing Street after an audience with Queen Elizabeth II to seek her permission to dissolve the British parliament to pave the way for a snap general election on Dec. 12. The monarch agreed to his request, he said.

In what was his first official speech in the general election campaign, Johnson said he did not want an election, but one had to be called because the British parliament was frustrating Brexit. He called for a majority government so work can start in December on Britain leaving the EU in January to end the uncertainty.

"We can leave the EU as one UK, whole and entire," he said, adding if Labour won the election Britain would spend the whole of 2020 in a horror show of dither and delay.

Johnson said: "Imagine waking up on Friday December 13 and finding (Labour leader Jeremy) Corbyn at the head of his technicolor yawn of a coalition. They would spend the whole of 2020 having two referendums. One on Scotland, and another referendum on Brexit, which is meant to happen in nine months time."

Johnson, like Corbyn and the other party leaders, will spend the coming weeks criss-crossing Britain to seek support ahead of the general election.