LONDON — Britain’s former defense secretary ferociously denied allegations that he leaked details from private government discussions about the Chinese telecommunications company Huawei, as opposition leaders called Thursday for a criminal investigation into the scandal.

Meanwhile, military analysts expect little fallout from his departure.

Gavin Williamson was fired from the government’s top defense job Wednesday by Prime Minister Theresa May, who said she had seen “compelling evidence” that he was behind media reports that the government had agreed — against the advice of the United States — to let Huawei participate in some aspects of Britain’s new 5G wireless communications network.

It was the first time in decades that a senior minister has been fired over leaks of sensitive information. Penny Mordaunt was quickly named as his replacement.

Williamson hit back, telling Sky News that the investigation had been a “witch hunt” and claiming he was the victim of a “kangaroo court with a summary execution.”

"I swear on my children's lives I did not" leak, he told the Daily Mail.

At 42, Williamson was Britain’s youngest-ever defense secretary, but had raised hackles among some colleagues with his ambition and occasional gaffes. After former spy Sergei Skripal was poisoned with a nerve agent in Salisbury — an attack that Britain blames on Moscow — Williamson said Russia should “go away and should shut up.”

Critics said that sounded more like playground language than diplomatic rhetoric. Another interesting tidbit: Williamson kept a large poisonous spider as a pet in his office in Parliament when he was Tory chief whip.

That said, Williamson also fought in the Ministry of Defence’s corner against the Treasury and others when it came to trying to secure more funding for the cash-strapped military. He secured an extra £1.8 billion (U.S. $2.4 billion) last year, and was embroiled in a battle to win a significant budget increase in funding for the next three years as part of the governmentwide comprehensive spending review due later this year.

“Williamson’s single merit in my view was that he fought for defense in a manner that few if any of his recent successors had,” said Howard Wheeldon, a defense analyst in the U.K. and consultant at Wheeldon Strategic. “He deserves much credit for that albeit that his lack of understanding for diplomacy and poor communication skills were a major weakness.”

“On the plus side, Penny Mordaunt, his successor, does at least bring some knowledge with her from her time as a defense minister under David Cameron,” Wheeldon added. “As member of Parliament for Portsmouth, she also brings useful Royal Navy-based maritime knowledge and skills to the job. We should welcome that.”

Analysts also expect Mordaunt to continue what Williamson began in driving defense funding, perhaps with greater success in the long term.

“New Secretary of Defence Penny Mordaunt will have a tough job to get more funding for her department, but any failure to do so won’t be for lack of willingness or dedication on her part,” said Alex Ashbourne-Walmsley, a defense consultant at ASC consultancy in London. “Regardless of the incumbent of the top job, defense faces a tough challenge because it is not seen as a ‘vote winner’ by many politicians or the wider public. But it is virtually certain that the new secretary of defense will have a better relationship with the prime minister than the outgoing one, and this can only be good for defense.”

Allies of Williamson rallied to his support Thursday, demanding that May’s government publish the evidence against him.

"Natural justice requires that the evidence is produced so that his reputation can be salvaged or utterly destroyed," said Conservative lawmaker Desmond Swayne.

Williamson was named in a Daily Telegraph report last week as being one of several ministers alleged to have opposed letting Huawei work on Britain's 5G infrastructure.

The United States has been lobbying allies, including Britain, to exclude Huawei from all 5G networks, claiming that the Chinese government can force the company to give it backdoor access to data on its networks.

Opposition Labour Party deputy leader Tom Watson said the leak from a top-secret meeting of Britain’s National Security Council was “indicative of the malaise and sickness at the heart of this ailing government.” He called for a criminal investigation into leaks from the security council, which is made up of senior ministers who receive briefings from military and intelligence chiefs.

Cabinet Office Minister David Lidington said the government did not plan to refer the matter to police. “But we would of course cooperate fully should the police themselves consider that an investigation were necessary,” he told lawmakers.

Metropolitan Police chief Cressida Dick, however, said the force would only investigate if it received a complaint.

Williamson is the second secretary of state for defense in a row to leave in controversial circumstances. His predecessor, Michael Fallon, departed after being accused of inappropriate behavior toward women. ‎Mordaunt was expected to be selected, but the job unexpectedly went to Williamson despite him having no ministerial experience.

“To say that Gavin Williamson was liked by the military would be an overstatement,” Wheeldon said. “He was appreciated by them for the manner in which he stood up to the Treasury, Cabinet Office and National Security Council, but that is where it started and ended. For the rest of the time he was merely tolerated.”