BREXIT will enable Britain to “think big,” Boris Johnson has insisted, as he made clear his determination to continue as Prime Minister amid mutterings that Tory backbenchers might seek a change of leader ahead of the 2024 General Election.

As the UK entered its first full week beyond the end of the transition period with many businesses and individuals fearing a wave of red tape, Mr Johnson admitted: “The tragic reality of business life is that there is some bureaucracy.”

But he stressed: “We’re trying to remove it but we have a massive opportunity to expand our horizons and to think globally and to think big. And this is the moment for this country.”

When challenged by the BBC’s Andrew Marr over the 159 pages setting out the UK Government’s handbook of rules for exporters to the EU, the PM replied: “Of course, there are going to be changes and we made that clear…There’s a great opportunity for British SME’s and for exporters of all kinds.”

He explained how firms had “already got substantial sums of money coming back to them, to this country, as a result of leaving the EU”.

Pressed on whether he would seek to remain in Downing Street after finally taking the UK out of the EU, Mr Johnson declared: “Yes, yes.”

He told Mr Marr: “You should break out of your characteristic gloom, if I may say so Andrew. Things are very tough; we’re going through a very tough period as a country but I really think people should focus on the amazing fact this country has created a room-temperature vaccine which can be used around the world.

“And we now have freedoms that we haven’t had for 50 years and there are lots of reasons to be very positive about this otherwise grim new year.”

Privately, some Conservative MPs have expressed alarm at the PM’s handling of the Government response to the pandemic, particularly the string of U-turns, which, they believe, has made ministers the victims rather than the masters of events.

With opinion polls beginning to show a rise in support for Labour under the leadership of Sir Keir Starmer, it is thought the Conservative Party will have to decide in the next 18 months whether to stick or twist with Mr Johnson; the general thinking is a new leader will need at least a year before the 2024 election to create a new frontline team and formulate their own election strategy.

Meanwhile, Tony Blair emphasised how decisions for Britain had always rested with the British people as he compared Brexit to “shock therapy”.

The former PM said: “There is nothing that Brexit’s going to do for Britain on its own; it’s going to leave us economically weaker and with less political influence.

“And so, the only way I make sense of Brexit is to treat it as shock therapy; that we then realise we’ve got to take certain big decisions as a country, we’ve got to set out a new agenda for the future, but that’s going to be difficult to do.”

The ex-Labour leader added: “These so-called freedoms from European regulation that Brexit’s supposed to give us, they don’t really give us anything much at all.

“Because the truth is that decisions for Britain are and always have been resting with the British people and with the British Government that they elect.

“But what it does mean, if we just carry on having the same old political debate post-Brexit as we had pre-Brexit, we’re in a lot of trouble as a country.”

Elsewhere, Priti Patel said she was prepared to give policing and security agencies “even tougher powers to keep this country safe” after the UK’s exit from the EU.

The Home Secretary talked up the post-Brexit trade and security deal that was hammered out as the clock ticked down to withdrawal from the bloc, insisting the UK would now be in a better position to protect its borders.