Britain's Prime Minister Theresa May leaves 10 Downing Street in London, Britain July 20, 2016.  [Photo/Agencies]

LONDON - Theresa May used her first parliamentary grilling as Britain's new prime minister on Wednesday to taunt the opposition over women's' rights, pointing out that it was her party that had made her the country's second female leader after Margaret Thatcher.

After a week of many firsts, May made her most closely watched debut, taking to the floor in parliament to lead the combative centrepiece of the British political week: Prime Minister's Questions.

May was appointed to Britain's top job a week ago after David Cameron resigned following the country's vote to quit the European Union, leaving her the difficult task of uniting the Conservative party and negotiating an exit from the bloc.

She won loud cheers from the Conservative Party benches in the debating chamber as she stood to face the daunting array of questions usually levelled at the prime minister during the 30-minute grilling, which can range from major foreign policy issues to parochial affairs.

May, who styles herself as a down-to-earth, unflashy leader, kicked off her remarks in the house by welcoming a drop in unemployment and setting out plans to visit German Chancellor Angela Merkel and French President Francois Hollande.

But she also picked up where Cameron left off last week, laying into the opposition Labour Party, whose leader Jeremy Corbyn is locked in a bitter internal power struggle in which the only female candidate to replace him dropped out on Tuesday.

"In my years here in this house I've long heard the Labour Party asking what the Conservative Party does for women, well it just keeps making us prime minister!," she said, to huge cheers from her own party as her husband looked on from the public gallery.

She added: "The Labour Party may be about to spend several months fighting and tearing itself apart. The Conservative Party will be spending those months bringing this country back together."

Often the only taste of parliamentary business that members of the public regularly get, the box-office drama known colloquially as PMQs is seen as a barometer of how well party leaders are doing and they are known to spend hours preparing.

Former Conservative leader Iain Duncan Smith on Wednesday told ITV the session was "the single most nerve-wracking thing you'll ever do in your life".

Cameron made his final appearance at PMQS last week with a relaxed and jokey performance that focused on mocking Corbyn and defining his legacy, before receiving a standing ovation as he left the chamber.