LONDON, June 12 (Xinhua) -- Former British foreign secretary Boris Johnson launched his bid Wednesday to become Britain's next prime minister, insisting that he does not want a no-deal Brexit.

Outlining his own manifesto in central London, Johnson, the hot favorite to win the keys to 10 Downing Street next month, said Britain must prepare for a no deal outcome.

Johnson said a no-deal Brexit was a last resort but the best way to avoid that outcome was to prepare for it.

"I am not aiming for a no-deal outcome, but it is only responsible to prepare vigorously and seriously for no-deal," he said.

Johnson added: "I think it is right for our great country to prepare. I will hit the ground running and engage in friendliest possible way with friends across channel."

Out of 10 contenders seeking to succeed Theresa May as leader of the Conservative Party, Johnson's leadership launch has been eagerly awaited.

He insisted the government must deliver the decision of the British people who voted to leave the European Union, and Britain must leave on Oct. 31, the deadline set by Brussels.

"If we now block it (Brexit) we will reap the whirlwind, we will face mortal retribution from the electorate. It is now time to end the debilitating uncertainty," Johnson said.

He said he would not pretend everything was going to be plain sailing, adding he believed that maturity and sense of duty will prevail to get Brexit done.