Britain's New Prime Minister Boris Johnson is welcomed into 10 Downing Street by staff. Picture: Stefan Rousseau/Pool Photo via AP
London - Britain's new Prime Minister Boris Johnson named the first of his new front bench ministers on Wednesday night, just hours after moving into 10 Downing Street. 

In what has been the biggest political reshuffle since the early 1960s, more than half of government ministers who served under former Prime Minister Theresa May were either sacked or resigned. 

As Johnson handed out jobs, thousands of protesters converged in Whitehall Wednesday night, gathering around the entrance to Downing Street. Officers from the Metropolitan Police were forced to form a line across the entrance to Downing Street. 

Reacting to the big changes at the top, Tom Watson, deputy leader of the main opposition Labour Party, said: "This huge cull will lead to early collapse of Johnson's government, bringing a general election that much closer." 

The call for a speedy general election was echoed by Labour leader Jeremy Corbyn who said: "We need a General Election and a Labour government that works for the many not the privileged few." 

Sajid Javid, who was Home Secretary in May's government, was named as new Chancellor of the Exchequer, succeeding Philip Hammond who resigned.  Now in charge of interior matters as the new Home Secretary is 47-year-old Priti Patel, who served under May as International Development Secretary until she resigned. 

The new Foreign Secretary is former Brexit Secretary Dominic Raab. He replaces Jeremy Hunt, the politician who went head-to-head with Johnson in the battle to be leader of the Conservative Party. 

Media reports claimed Hunt had been offered a new job in Johnson's government but rejected what he considered a demotion from the Foreign and Commonwealth Office. 

In an extraordinary day in British politics, outgoing Prime Minister May ended her last day in office at her final Prime Minister's Question Time. 

May then made the short journey to Buckingham Palace to offer her resignation to Queen Elizabeth, followed soon after by Johnson's journey to the palace, to be invited by the British monarch to form the new government. He then headed to his new home at 10 Downing Street where among the people waiting to greet him was his girlfriend Carrie Symonds. 

In a rousing speech Johnson promised that Britain would leave the European Union on Oct. 31. 

Behind the world's most famous front door, Johnson quickly started to hand out the first key posts in a team that will be made up mainly of Brexit supporters. 

One of the few front benchers to stay in the same job, Steven Barclay, remains in Johnson's cabinet as Brexit Secretary. He had replaced Raab when he quit. 

Also remaining in his old job is Health Secretary Matt Hancock. Former security minister Ben Wallace, the new Defense Secretary, campaigned to remain in the European Union. He trained at Britain's top military academy, Sandhurst, and later joined the famous Scots Guards, serving in the military for eight years. 

Loyal Johnson supporter Liz Truss has been appointed International Development Secretary. She was second-in-command at the Treasury in May's cabinet and in 2016 became the first female Lord Chancellor. 

There was also a top job for former Environment Secretary Michael Gove who had a spectacular fall-out with Johnson in the 2016 leadership election which saw Theresa May emerge as prime minister. In that campaign Gove scuppered the leadership hopes of Johnson by announcing his own candidature on the morning Johnson was due to launch his campaign. 

Johnson stunned his allies by withdrawing from the contest. 

Gove was also a contender in the recent contest for the leadership of the Conservative Party. Political commentators said it appeared Johnson and Gove have "buried the hatchet", with Gove appointed as Chancellor of the Duchy of Lancaster. The holder of the title is usually the de-facto deputy prime minister. 

In his first speech as prime minister, on the steps of Downing Street, Johnson said he had a message for the doubters, the doomsters and the gloomsters, adding "they are going to get it wrong again. The people who bet against Britain are going to lose their shirts." 

"We are going to fulfill the repeated promises of parliament to the people and come out of the EU on Oct. 31, no ifs or buts," he said. 

"And we will do a new deal, a better deal that will maximize the opportunities of Brexit while allowing us to develop a new and exciting partnership with the rest of Europe based on free trade and mutual support. I have every confidence that in 99 days' time we will have cracked it." 

Johnson will continue assembling his ministerial team over the next few days. 

Xinhua