Prime Minister Theresa May on Thursday named Gavin Williamson as Britain's new defence secretary after his predecessor Michael Fallon was forced to step down over a sexual harassment scandal sweeping parliament.
It represents a significant promotion for the 41-year-old Williamson, a trusted ally whose former job as chief whip involved enforcing discipline for May's Conservative Party in parliament.
Williamson, who was only elected to parliament in 2010, is best known for having a pet tarantula, Cronus, that he keeps in a glass-sided tank on his desk.
The new defence minister said he was "honoured and excited" by the promotion, adding he was "determined to ensure that the armed forces receive the recognition they deserve".
But some questioned Williamson's expertise for the job, considered one of the biggest and most challenging in the British government.
According to "TheyWorkForYou", an online record of parliamentary activity, Williamson has asked only seven questions on defence since 2010.
May's Downing Street office responded that Williamson "was an excellent and hard-working chief whip and the prime minister thinks he will make an excellent defence secretary".
Britain, a major member of the NATO military alliance, spends two percent of its gross domestic product (GDP) on defence but the armed forces are facing constant pressure to cut costs.
Fallon announced his resignation late Wednesday, the first casualty of a deepening scandal over sexual harassment in British politics.
He had apologised earlier in the week for touching a journalist's knee in 2002, but reports suggested there were other allegations which had not yet been made public.
"I accept that in the past I have fallen below the high standards that we require of the armed forces that I have the honour to represent," Fallon said.
Williamson was May's parliamentary campaign manager when she successfully ran to become Conservative Party leader, and was rewarded with the job of chief whip.
In this role, he had responsibility for ensuring that ruling party MPs attend votes, and vote according to party lines, a tough task in the recent votes on Brexit legislation given the rifts within the party over the issue.
He also had to keep the centre-right party together following the disastrous performance in the June snap general election, when May lost her parliamentary majority, spurring calls for her resignation.
Julian Smith, one of Williamson's closest allies, was named new chief whip, raising suggestions that the incoming defence minister had orchestrated the reshuffle.
BBC News political editor Laura Kuenssberg tweeted that a minister had told her that May was "so weak she has let Williamson appoint himself -- this is appalling".
The move raised questions about whether the whips' office had a role in preparing the dossier on ministers that is behind the scandal, and there were reports that Williamson advised May that Fallon may be facing further allegations.
"Make no mistake, Gavin Williamson wants to be prime minister. And he knows all the dirt on his colleagues," wrote Tim Shipman, political editor of The Sunday Times newspaper.
May's spokesman insisted that Williamson "wasn't involved in the reshuffle" but wouldn't say whether he was involved in discussions about Fallon's departure.
"Where allegations are brought to the whips they are then brought forward and dealt with in the proper way," he said.
By promoting Williamson from the whips' office, May has avoided a wider reshuffle of senior cabinet ministers.