Johnson sacked Northern Ireland Secretary Julian Smith who had been widely praised for helping to end political deadlock Several high-profile women in Johnson"s government all said they had been fired on Thursday morning LONDON: British Prime Minister Boris Johnson has appointed Rishi Sunak as his new finance minister, the government said in a statement on Thursday. Sunak, 39, who previously served as Chief Secretary to the Treasury, the second in command to the finance minister, succeeds Sajid Javid who has resigned. Javid resigned Thursday, in a shock development on the day that Prime Minister Boris Johnson is shaking up his Conservative government. Javid had been widely expected to keep his job in the Cabinet shakeup. But a spokesman confirmed Thursday that he had quit. Javid"s resignation follows reports he had clashed with Johnson"s powerful adviser, Dominic Cummings. Javid had been due to deliver his annual budget next month. His resignation shakes the government as it faces the challenges of negotiating a new relationship with the 27-nation EU by the end of this year. Johnson also has ambitious infrastructure plans including a 100 billion-pound ($130 billion) high-speed railway. Britain"s Press Association news agency reported that Javid had quit after being told to fire all his aides and replace them with staff appointed by the prime minister"s office. Johnson shook up his government on Thursday, firing and appointing ministers to key Cabinet posts. Johnson was aiming to tighten his grip on government after winning a big parliamentary majority in December’s election. That victory allowed Johnson to take Britain out of the European Union last month, delivering on his key election promise. Now his Conservative administration faces the even bigger challenge of negotiating a new relationship with the 27-nation EU by the end of this year. The two sides are aiming to have a deal covering trade, security and other areas in place by the time a post-Brexit transition period ends on Dec. 31. So far, the two sides are far apart in their demands. And even with a deal, the UK faces a huge adjustment when decades of seamless trade and travel with the EU end at the start of 2021. Several high-profile women in Johnson"s government, including Business Secretary Andrea Leadsom, Environment Secretary Theresa Villiers and Housing Minister Esther McVey, all said they had been fired on Thursday morning. Johnson also sacked Northern Ireland Secretary Julian Smith — a surprise move. Smith had been widely praised for helping to end political deadlock that left Northern Ireland without a regional government and assembly for three years. After pressure from the British and Irish governments, the main Irish nationalist and British unionist power-sharing parties returned to work last month. As well as reworking his Cabinet, Johnson needs to appoint a new leader for the UN climate change conference that Britain is due to host later this year. The summit, known as the 26th Conference of the Parties, or COP26, is scheduled to be held in Glasgow in November. Planning has got off to a rocky start, with Johnson last week firing Claire O"Neill, a former British government minister appointed last year to head up the event.