Prime Minister David Cameron promised to "tighten the law and change the culture" by cracking down on tax evasion and discouraging "aggressive" tax avoidance on Monday, following the British use of tax havens revealed in the Panama Papers.
Britain's tax authority and national crime agency will examine possible tax evasion and money laundering by British companies and individuals identified in leaked documents from the Panama-based Mossack Fonseca law firm, Cameron told parliament.
But people should "defend the right of every British citizen to make money lawfully," he said, placing his government "at the forefront of international action to tackle the global scourge of aggressive tax avoidance and evasion."
Cameron has faced political pressure since his father's offshore investment company, which legally avoided British taxes by registering in tax havens, was named last week in leaked documents from the Panama Papers.
He told parliament he sold his shares in one of his father's funds in early 2010, shortly before he became prime minister, "because I didn't want any issues about conflict of interest."
Cameron has admitted fault for his widely criticized response last week, when he gave a series of brief statements on his links to the Panama Papers rather than a full disclosure.
"I accept all of the criticisms for not responding more quickly to this issue last week," he said on Monday.
Replying to Cameron in parliament, opposition Labour leader Jeremy Corbyn called for a "credible and independent investigation" of tax avoidance through tax havens.
Corbyn said Cameron had still "failed to give a full account" of his financial affairs, despite publishing summaries of his tax returns on Sunday, and said the prime minister's handling of the Panama Papers leak showed the public "no longer have trust in him."
David Gauke, financial secretary to the Treasury, said earlier that the Panama Papers showed "tax evasion is part of a wider set of international criminality ... together with money laundering, illicit finance and evading sanctions."
"The new taskforce announced today will further tighten the screw on those who think they can get away with dodging tax that's due in this country," Gauke said. "Our message is clear: there are no safe havens."
Before Monday's announcement, police and tax officers were already investigating 700 "current leads with a link to Panama," the government said.
The government will also introduce new legislation to "hold companies who fail to stop their employees facilitating tax evasion criminally liable," Cameron said.
Cameron then came under renewed pressure after he published tax summaries on Sunday that show a 200,000-pound (280,000-dollar) gift from his mother. He had previously admitted to having inherited 300,000 from his father and sold shares in his father's offshore investment fund for some 30,000 pounds.
He initially said his father's registration of offshore funds in tax havens was "a private matter."
Cameron then made statements saying that he and his immediate family held no offshore assets and would not benefit from offshore holdings in the future.