David Cameron will be challenged over the long-standing links between scandal-hit HSBC and the Conservative Party, after Electoral Commission records showed three senior bank figures have donated £875,000 to the party in recent years.

As Downing Street came under more pressure over this week’s revelations that the bank allegedly helped wealthy individuals evade tax through Swiss accounts, it was revealed that HSBC’s deputy chairman, Sir Simon Robertson, has made 24 separate donations totalling £717,500 in the last nine years.

He gave 17 donations to the Conservative Central Office between 2002 and 2014, and four totalling £100,000 to George Osborne between 2006 and 2009. The other three went to the party in East Hampshire. Sir Simon, who was knighted in 2010, is reported to have a personal wealth of £10m.

The Conservatives will face scrutiny over senior HSBC figures' donations (Getty) (Getty Images)

Stewart Newton, who was a director of HSBC Holdings from 2002 to 2008 has donated £128,000 between 2001 and 2013, including payments to the Tory associations in marginal seats in Sussex, Essex and Suffolk. And Sir Adrian Swire, who was an HSBC director between 1995 and 2003, has given £30,000 to the party between 2003 and 2014.

Labour also pointed to the appointment of Dave Hartnett, the HMRC permanent secretary under Mr Osborne, and of Lord Rose, a Tory peer, as HSBC advisers as evidence of close links between the bank and the party. The Labour MP Sheila Gilmore said: “The revolving door between David Cameron’s government and HSBC casts new light on this Government’s failure to act over alleged wrongdoing.”

A Number 10 spokeswoman originally said neither Lord Green, a former Tory minister, or any other ministers had “any knowledge that HSBC may have been involved in wrongdoing in regard to its Swiss banking arm prior to the reports of the last couple of days”.

Sir Simon Robertson made donations worth £717,500 (Getty) (Getty Images)

Later, she said the Government “have no record” that any government minister was made aware of the allegations by HMRC.

Meanwhile Martin Wheatley, chief executive of the Financial Conduct Authorities (FCA), told MPs on the Treasury Committee that “frankly the chief executives don’t know about the skeletons in their organisations”. He also said that financial watchdogs were not alerted to the allegations about the activities of HSBC’s Swiss unit until they emerged in the media.

Treasury Committee chairman Andrew Tyrie questioned whether HSBC and other banks have become “too big too manage”.

Major donors to the Conservative Party Show all 10 1 /10 Major donors to the Conservative Party Major donors to the Conservative Party Michael Farmer Hedge fund: RK Capital Management Worth: £150m Total donation: £6,556,092 Rex Features Major donors to the Conservative Party Sir Michael Hintze Hedge fund: CQS Worth: £1,055m Total donation: 3,221,027 Major donors to the Conservative Party Lord Fink Hedge fund: ISAM Worth: £130m Total donation: £3,172,007 EPA Major donors to the Conservative Party Chris Rokos Hedge fund: Brevan Howard (pictured) Worth: £230m Total donation: £1,344,850 Google Street View Major donors to the Conservative Party Andrew Law Hedge fund: Caxton Associates Worth: £350m Total donation: £1,226,411 Rex Major donors to the Conservative Party Sir Paul Ruddock Hedge fund: Lansdowne Partners Worth: £300m Total donation: £818,783 Rex Major donors to the Conservative Party David Harding Hedge fund: Winton Capital Worth: £750m Total donation: £593,765 Major donors to the Conservative Party Hugh Sloane Hedge fund: Sloane Robinson Worth: £185 Total donation: £533,500 Major donors to the Conservative Party Sir John and Peter Beckwith (L) Hedge fund: RiverCrest Capital Worth: £350m Total donation: £520,996 Rex Major donors to the Conservative Party Alexander Knaster Hedge fund: Pamplona Capital Management Worth: £1,266m Total donation: £400,000

Speaking after the hearing, he added: “Martin Wheatley today told the Committee that the CEOs of the banks don’t know about all the skeletons in their organisations’ cupboards. It is now more than two years since they promised the Parliamentary Commission on Banking Standards that they were tackling poor behaviour, reforming their culture and turning a corner. Clearly much more still needs to be done.”

HMRC later said it had been unable to share information with the FCA under the terms of a treaty with the French authorities.

HSBC also came under pressure from business secretary, Vince Cable, who has written to the bank questioning how quickly its Swiss private banking arm stopped practices which may have helped customers avoid tax.