* Tax avoidance hot issue before May 7 national election
* Cameron under pressure over HSBC scandal
* Labour says he has serious questions to answer
* Cameron says he and party acted properly (Recasts, adds quotes, context)
By Andrew Osborn
LONDON, Feb 11 (Reuters) - British Prime Minister DavidCameron came under pressure in parliament on Wednesday over atax scandal engulfing HSBC's Swiss arm when the oppositionLabour Party accused Cameron's party of accepting donations from"dodgy" HSBC account holders.
Cameron did not dispute the donations -- from seven unnamedindividuals -- and there is no suggestion the account holdersdid anything illegal. But the disclosure is awkward for Cameronthree months before a close national election on May 7.
It allowed Labour, level with Cameron's Conservatives inmany opinion polls, to press its portrayal of Cameron and hisparty as putting the interests of the wealthy before those ofthe less well-off. Cameron rejects that charge.
"How can the prime minister explain the revolving doorbetween the Tory (Conservative) Party HQ and the Swiss branch ofHSBC?" Labour leader Ed Miliband asked Cameron in parliament. "He's a dodgy prime minister, surrounded by dodgy donors."
Cameron laughed off the broadside.
"For 13 years they sat in the Treasury, they did nothingabout tax transparency, nothing about tax dodging, nothing abouttax avoidance," he said of Labour.
After the leak this month of its Swiss bank's customer list,HSBC admitted failings in compliance and controls at the unit.
Cameron is also under pressure from Labour over his 2010appointment of Stephen Green, HSBC's former executive chairman,to be a peer and a trade minister, a role he no longer fulfils.
Cameron said on Wednesday that "every proper process" wasfollowed when he appointed Green when pressed by Miliband if heknew about the HSBC allegations when he appointed him.
Miliband, who asserted HSBC had enabled tax avoidance on "anindustrial scale", focused on the party funding issue however,accusing Cameron's party of accepting donations worth nearly 5million pounds ($7.65 million) from seven unnamed holders ofHSBC Swiss accounts.
Cameron said he had seen the same list of names and that itincluded the name of a British peer who had donated money to theelection campaign of Miliband's predecessor as Labour leader.
So far, Green, 66, has declined to comment. HSBC said itcouldn't relay questions to Green, nobody at his office in theupper house of parliament answered the phone, and theConservatives said they couldn't speak for ministers or peers.
($1 = 0.6538 pounds) (Additional reporting by Kylie MacLellan and Stephen Addison;Editing by Ralph Boulton)