SNP leader Alex Salmond was last night accused of pandering to "homophobia" by accepting a £500,000 donation from an anti-gay businessman.

The SNP yesterday confirmed that Brian Souter, who financed a high-profile campaign to keep Section 28, which banned "promoting" homo-sexuality in schools, was bankrolling their election hopes with a cheque for £500,000.

Salmond was immediately criticised by gay rights campaigners and was called on to clarify his party's view on equality issues.

The dramatic announcement of Souter's donation was made at the SNP's pre-election conference in Glasgow's Govan, a seat the party hopes to win from Labour.

Souter, a self-made millionaire and bus tycoon, is a known Nationalist supporter who used to make donations to the party in the 1990s.

However, he fell out with the SNP in 2000 after fronting a high-profile campaign to prevent the Scottish Executive from lifting the bar on promoting homosexuality in schools.

Souter, a fundamentalist Christian, ploughed £1 million into the Keep The Clause Campaign and bankrolled a private referendum to gauge Scottish opinion on the inflammatory subject. He then proceeded to outrage liberal opinion with a campaign perceived to be homophobic.

Souter yesterday said Scotland had a right to self-determination: "As long as I can remember, the case for the union has been hugely financed by cash from London, while the case for independence has lacked resources. I hope my donation will help redress this imbalance.

"The time has come for Alex Salmond to deliver a dynamic government in Scotland which will respect our past, respond to our present problems and reflect the future aspirations of the Scottish people."

But the donation enraged equality activists who fear the SNP have abandoned their support for gay rights.

Tim Hopkins of the Equality Network said: "I worry that the SNP have decided they can get more votes from homophobes than from the gay community. What is Brian Souter expecting for his half a million? People will rightly be asking if the SNP still supports equality."

He added that the SNP recently backed the right of Catholic adoption agencies to turn away gay couples and said the Nationalists pointedly snubbed a gay rights debate in January.

"All parties were present, including the Tories, but not the SNP. We wrote to deputy leader Nicola Sturgeon about whether they were in favour of equality and we never got a response."

Veteran gay rights campaigner Peter Tatchell also condemned the SNP: "This is an outrageous insult to every gay person in Scotland. The SNP would never accept a donation from an avowed racist, so why are they accepting funding from a man who is so clearly homophobic?"

Green MSP Patrick Harvie said: "The Keep The Clause campaign was deceitful, manipulative and bigoted. Brian Souter's referendum was an utter sham. I invite the SNP to disassociate themselves from that sort of campaigning."

A source close to the SNP leader played down the Section 28 controversy, and said the Souter donation had "nothing to do with any moral agenda". And Salmond welcomed the donation, saying: "Brian Souter is one of the outstanding entrepreneurs of his generation. I am very grateful for his support."