Video report by ITV News political correspondent Libby Wiener.
Theresa May launched a series of scathing attacks on Jeremy Corbyn during her first appearance at Prime Minister's Questions.
The prime minister mocked the Labour leader as he raised the issue of "unscrupulous bosses", suggesting he might be reminded of "a boss who doesn't listen to his workers", a thinly-veiled attack on his refusal to resign.
Mrs May said the Labour Party was about to spend months "fighting and tearing itself apart" during a leadership battle, while the Government spends the time "bringing this country back together".
In her first appearance at the dispatch box, Mrs May was cheered on by Conservative MPs, with many clearly impressed by her performance.
- May taunts Corbyn over leadership challenge
Mrs May won loud cheers as she sought to twist the knife into Mr Corbyn over the turmoil in his party's ranks.
"I am interested that he refers to the situation of some workers who might have some job insecurity and potentially unscrupulous bosses," she said.
"I suspect that there are many members on the Opposition benches who might be familiar with an unscrupulous boss.
"A boss who doesn't listen to his workers, a boss who requires some of his workers to double their workload and maybe a boss who exploits the rules to further his own career. Remind him of anybody?"
As Mr Corbyn, who is facing a leadership challenge from Owen Smith, complained that there were "many people in this country struggling with insecure jobs", he was met with raucous laughter from Tory MPs.
The Labour angrily hit back, saying: "I know this is very funny for Conservative members but I do not suppose (there are) too many Conservative MPs who have to go to a food bank in order to supplement their family table."
The prime minister said that the answer was a "strong economy", adding that the Government was focused on "building a country that works for everyone".
Mrs May said: "Labour may be about to have several months of fighting and tearing itself apart. The Conservative Party will be spending those months bring this country back together."
- Labour leader under attack from all sides
It was not only Mrs May who Mr Corbyn had to worry about during PMQs, as he was mocked by one of his own MPs for his stance on the UK's Trident nuclear deterrent.
Mr Corbyn opposed a motion to renew the deterrent earlier this week, earning him strong criticism from many in his own party.
At PMQs today, Labour MP Jamie Reed thanked Theresa May for her "wholehearted support and endorsement for official Labour Party policy on Trident".
"It's such a refreshing change to hear that from the dispatch box," he said as Mr Corbyn sat stony-faced on the front bench.
Mrs May pointedly praised the 141 Labour MPs who "put the national interest first" and voted in favour of renewing the nuclear deterrent in Monday's Commons vote.
- New PM dodges question about Boris Johnson appointment
Earlier, Mr Corbyn raised comments made by Boris Johnson before he became foreign secretary.
Mr Corbyn said Mrs May is rightly concerned about the harsh treatment of black people compared to white people.
He asked: "Before appointing your new foreign secretary, did you discuss with him his description of black people as piccaninnies and why he questioned the motives of the US president Obama on his part-Kenyan heritage?"
Mrs May, in her reply, said: "It is correct that if you're black you will be treated more harshly in the criminal justice system.
"It's exactly why as Home Secretary I dealt with the issue of stop and search. I was concerned to make sure that nobody should be stopped and searched on the streets of this country because of the colour of their skin.
"I did that as a Conservative - 13 years of Labour did nothing on it."
Mr Corbyn countered: "My question was actually about the language used by the Foreign Secretary."
- Conservative Party 'keeps making women prime minister'
In their opening exchanges, Mr Corbyn congratuled Mrs May on becoming the second female prime minister, adding: "I hope you will agree with me that this House and Prime Minister's Question time should be an opportunity to debate seriously the issues that face our country and our place in the world."
Mrs May replied: "You refer to me as the second woman prime minister. In my years here in this House I've long heard the Labour Party asking what the Conservative Party does for women - well, just keep making us Prime Minister."
- Analysis: commentators impressed by May's performance
Mrs May's first appearance at PMQs was always going to be closely scrutinised, and many commentators appeared impressed with her performance.
Some compared her performance to that of former Prime Minister Margaret Thatcher.
ITV News political correspondent Carl Dinnen said Conservative MPs were delighted after Mrs May "wiped the floor" with Mr Corbyn.
Isabel Hardman, assistant editor of the Spectator magazine, told ITV News that Mrs May displayed "an incredibly calm authority" during PMQs.
Meanwhile, Mrs May herself just seemed glad when the whole thing was over, breathing a sigh of relief at the end of PMQs.