George Osborne
The Chancellor is facing growing pressure not to remain tight-lipped on his personal tax affairsSuzanne Plunkett/Reuters

Pressure is piling on Chancellor George Osborne to disclose details of his tax returns after Scottish National Party (SNP) leader Nicola Sturgeon became the latest political leader to publish hers. It comes as the whole cabinet faces the prospect of having to release personal financial information, according to Conservative MPs.

SNP's Westminster leader, Angus Robertson said it must be determined whether senior cabinet ministers who decide on tax laws have prospered from tax havens. Writing to the prime minister, Robertson accused Osborne of hypocrisy for condemning tax avoidance while failing to be transparent by publishing his own tax returns.

"David Cameron has serious questions to answer and must provide full disclosure of his cabinet: how many government ministers have benefited from tax havens?" said Robertson. "We have yet to hear from George Osborne, or others."

A Treasury source responded: "We have been clear that the chancellor has never had any offshore shareholdings or other interests. His income and interests are straightforward and declared publicly: his salary, rental income from a property in London and a shareholding in his father's firm, Osborne and Little. He is always happy to consider ways to ‎offer even more transparency."

On 9 April, the prime minister released his tax records for the past six years in a bid to quell the fallout from the Panama Papers leak last week. It revealed that Cameron had received £200,000 ($282,000) as a gift from his mother in 2011 which will not be eligible for inheritance tax after 2018. He had also earned more than £1m in the past six years.

Speaking to the Times, one Tory MP said Cameron had "gone a bit too far" by publishing his tax details and said they would have a knock-on effect. Referring to the calls for Osborne to do the same, the unidentified source said: "The fact is, Dave has put him in this position."

Another Conservative MP said it would be "difficult" not to follow Cameron's example and asked: "It extends its reach to all those in public life and the key question is: where does it stop? BBC journalists, councillors, judges?"

But others said it was less clear-cut whether Osborne would also need to publish details of his personal tax affairs. "George [Osborne] has a case to not do so, because there's no query about his financial affairs as there was with David Cameron after the Panama papers," an MP said.

Sturgeon's tax returns revealed that she was paid more than £104,000 as first minister last year. She paid over £31,000 in tax. By publishing her personal financial information, she joined her fellow Scottish Labour and Conservative counterparts, Kezia Dugdale and Ruth Davidson respectively.

Opposition leader Jeremy Corbyn – who has promised to publish his tax returns shortly – said that Cameron still has more questions to answer. "I want to see the papers," he told the BBC's Andrew Marr show.

"We need to know what he's actually returned as a tax return, we need to know why he put this money overseas in the first place and whether he made anything out of it or not before 2010 when he became Prime Minister," Corbyn added.