Rishi Sunak is running for the position of leader of the Conservative Party, and as prime minister.
This former chancellor is perhaps the most prominent figure to announce his candidacy so far.
On Tuesday, his resignation from the cabinet triggered a mass walkout by ministers that led to Boris Johnson being forced to resign as Tory leader.
Johnson will remain in office as prime minister until the Tory party selects a successor.
Senior backbencher Tom Tugendhat, and Attorney General Suella Braverman already announced that they would stand.
In the meantime, former Foreign Secretary Jeremy Hunt and Defence Secretary Ben Wallace are believed to be looking at leadership bids. Former Brexit minister Steve Baker also indicated that he would mount a challenge.
Next week, a timetable will be established for the Tory leadership race and the new prime minster is expected to be in place by September.
Sunak announced his decision to stand in a video on social media and stated that he wanted "restore trust", rebuild the economy, and reunite the nation.
He said, "Someone must grasp this moment and make right decisions."
He asked, "Do we face this moment with honesty, seriousness, and determination? Or do we tell ourselves fairy tales that will make us feel better today but leave our children poorer tomorrow?"
He pledged to "lead this country in the right way" on the basis of values such as "patriotism", "fairness, and hard work."
He stated that the country was facing "huge problems" and that today's decisions would decide whether the next generation has "a chance for a better future."
He pointed out his leadership credentials and said that he had managed the "toughest government department" during the worst times of Covid.
Numerous Tory MPs from the top have supported Mr Sunak's candidacy. They tweeted their support, and promoted his campaign slogan "Ready for Rishi".
Mark Spencer, Commons Leader, wrote that Raji was the leader who can unify the Party, bring together the entire country and win us the fifth general election victory.
42-year-old Mr Sunak was an analyst at Goldman Sachs and later became a partner in two Hedge Funds. He was elected to the North Yorkshire constituency in Richmond in 2015.
Once, he was seen as the main contender to succeed Johnson as Conservative Party leader/prime minister.
In July 2020, Mr Sunak was appointed chancellor. He had to deal with the Covid-19 pandemic and spend huge sums to keep the economy afloat.
However, his reputation was damaged by the controversy surrounding his wife's tax affairs as well as being fined for violating lockdown rules during pandemic.
The Metropolitan Police fined Mr Sunak and Mr Johnson, together with his wife Carrie, because they broke Covid rules by attending a party for the prime minster in June 2020.
Supporter of Brexit, Mr Sunak was loyal and supportive to Mr Johnson, despite tensions about economic policy and the prime Minister's desire to reduce taxes faster as living costs rise.
Their relationship ended when Mr Sunak, a close ally and former Health Minister Sajid Javid, abruptly resigned.
Sunak stated in his resignation letter that the public expects government to be run properly, competently, and seriously.
In his resignation letter to the PM, Mr Sunak also mentioned tensions about the economy. He told the PM that their approaches were "fundamentally too divergent".
His resignation and Mr Javid's precipitated a mass exodus and precipitated Mr Johnson's downfall.
