Laura Kuenssberg
BBC political editor

Boris Johnson in a funny way tried to do what Theresa May did when she entered No 10 - to say yes, I am here to sort out Brexit, but here are things you care about as a country too.

But the new PM knows the reason he has won power was the part he played in the referendum campaign and his promise to party members to leave the EU by 31 October.

All the way through that statement, you could hear not just protests by anti-Brexiteers, but real arguments between the both sides. They may be small in number, but is a metaphor for how choppy it is going to be for Mr Johnson.

This is a very precarious political time and the chanting at the gates would have been a reminder.

The new Prime Minister praised the UK's "pluck, nerve and ambition" and said "it is time we look not at the risks but the opportunities we have upon us".

He finished his speech with a flair, adding: "We in this government will work flat out to give this country the leadership it deserves and that work starts now."

From tax rules through to welfare of animals, Mr Johnson lists a number of issues he wants to address in No 10.

"All this and more, we can do now, and only now at this extraordinary moment in our history," he says.

"After three years of unfounded self-doubt, it is time to change the record."

He adds: "No-one in the last few centuries has succeeded in betting against the pluck, nerve and ambition of this country.

"They will not succeed today."

New Prime Minister Boris Johnson tells the country: "It has become clear that there are pessimists at home and abroad who think after three years of indecision that this country has become a prisoner to the old arguments of 2016 and in this home of democracy we are incapable of honouring a democratic mandate.

"And so I am standing before you today, to tell you the British people, that those critics are wrong - the doubters, the doomsters, the gloomsters are going to get it wrong again."

Mr Johnson sends a message to the EU that he wants to do a deal, but he is still willing to leave without one - "not because we want that outcome, but because it is only common sense to prepare".

He says with "high hearts and growing confidence" the UK will be ready for whatever outcome.

The new PM adds: "Yes, there will be difficulties... but if there is one thing that has really sapped the confidence of business is not the decisions we have taken, it is our refusal to take decisions."

Mr Johnson says the union flag "stands for freedom, free speech... the rule of law and above all democracy. That is why we will come out of the EU on 31 October".

He says the choice to leave was a "fundamental decision" of the British people, but also says he wants those people already here to feel part of the UK.

Mr Johnson says he will do everything he can to tackle problems with social care and education straight away.

He says he will "take personal responsibility", adding: "The buck stops here".

Mr Johnson says he is sure the UK will "crack it" when it comes to leaving the EU on 31 October.

But, he adds "We aren't going to wait 99 days.

"The British people have had enough of waiting and the time has come to act to give strong leadership.

"My job is to serve you the people."

Boris Johnson pays tribute to the "fortitude and patience" of Theresa May, and her "deep sense of public service".

But, he says, despite of all her efforts "pessimists at home and abroad" see the UK as a " prisoner to old arguments of 2016".