May, who made repeated use of her party's mantra of "strong and stable leadership" under the Conservatives, said Labour would "crash" the economy if it won the election, and that a vote for Corbyn would damage Britain's ability to ensure the best terms for its exit from the European Union in two years' time.
"Every vote for you is a vote for a chaotic Brexit -- every vote for me is a vote to strengthen our hand in negotiating the best deal for Britain," she said.
Challenging May in Parliament, Corbyn accused her of failing to listen to voters -- citing her use of "handpicked audiences" who can't ask questions at campaign events -- and of leading a government that only serves the rich.
May in turn targeted Corbyn over his comments over the weekend that he would review "all aspects" of defense if Labor won the election, including Britain's Trident nuclear deterrent system.
"Again at the weekend, we saw the right honorable gentleman refusing to say he would strike against terrorism, refusing to commit to our nuclear deterrent, and refusing to control our borders," May said. "Keeping a country safe is the first duty of a Prime Minister; the right honorable gentleman is simply not up to the job."
Lawmakers packed the House of Commons for what could be the last opportunity for some to take part in Prime Minister's Questions, a weekly ritual which puts the Prime Minister under the spotlight as the leader of the opposition and backbench lawmakers pose their questions. Parliament is expected to break up on May 3 to allow the parties to focus on campaigning.
Corbyn: Conservatives 'only look after the richest'
In his remarks, Corbyn sought to frame the Conservatives as letting down the average voter on wages, health care, education, housing and pensions.
"Strong leadership is about standing up for the many, and not the few," he said. "But when it comes to the Conservatives, they only look after the richest and not the poorest. They are strong against the weak and weak against the strong. Far from building a strong economy, schools and our NHS are being cut, people cannot afford homes, and millions cannot make ends meet. That doesn't add up to a strong economy for anyone."
Liberal Democrat leader Tim Farron accused May of leading a party that "has never been nastier," having "closed the door on desperate child refugees" and ignored the plight of UK citizens suffering as health and social services struggle to keep up with demand.
May defended her government's record and warned against a "coalition of chaos" if Labour won enough seats to form a coalition government with the Liberal Democrats and Scottish National Party.
Speaker John Bercow was several times forced to call the chamber to order as feelings ran high.
Polls indicate Conservative lead
May's Conservative Party is leading the opposition Labour Party by a huge margin ahead of the election, several polls released this week show. Three polls suggest that about twice as many people plan to vote Conservative as Labour.
The Liberal Democrats, UK Independence Party and Scottish National Party trail behind the two main parties.
Because British voters elect the 650 members of parliament in 650 individual constituency elections, it's complicated to project how national polls will translate into numbers of seats per party.
An Ipsos-MORI poll published Wednesday indicated that three out of five of those surveyed said May would make the most capable Prime Minister, compared with just under a quarter who said that of Corbyn.
The election campaign is set to be dominated by the issue of Brexit, for which voters opted in a referendum a little under a year ago.
The UK government formally served divorce papers on the European Union
on March 29, signaling the beginning of the end of a relationship that endured for 44 years.