By Carmel Crimmins

DUBLIN (Reuters) - A gay senator has taken the heat off former Irish Republican Army (IRA) commander Martin McGuinness in the race for Ireland's presidency as controversies over his past dominate the campaign.

David Norris, a charismatic literary scholar, sought on Wednesday to end discord over his appeals for clemency for a former partner convicted of statutory rape and the disclosure he claimed disability benefit while working as a senator.

The controversies have taken the focus off McGuinness whose membership of one of the world's most deadly guerrilla groups has triggered stinging attacks from government ministers who fear his past could damage the figurehead role and whose own presidential candidate is languishing in the polls.

"I very much hope that we will be able to put this very sad episode behind and move on," Norris told a news conference to launch his campaign.

Norris' unwillingness to publish letters he wrote seeking clemency for his Israeli former partner, Ezra Nawi, over a sexual relationship with a 15-year-old Palestinian boy, has created a media storm and a dramatic fall in his ratings.

A poll to be published in Thursday's Irish Times newspaper showed he had lost his position as frontrunner and was now ranked fifth having dropped 14 percentage points to 11 percent from a survey in July.

McGuinness, who did not feature in the July survey because he only entered the race last month, was in third position on 19 percent. Former culture minister Michael D. Higgins, the candidate of the Labour party, the junior coalition partner, is now the favorite with 23 percent.

The ruling Fine Gael party's candidate was second to last with 9 percent and business man Sean Gallagher jumped seven points to be the second-favorite candidate with 20 percent.

A BIT OF CONTROVERSY

Norris' admission in July that he had asked a judge to be lenient toward Nawi came after comments he made in 2002 defending the Ancient Greek attitude to pederasty or sex between men and boys were published again. The subsequent controversy forced him to quit the race.

Norris released one letter he wrote on behalf of Nawi in August, written from his office in the Senate, but in a statement he read out on Wednesday he said lawyers in Ireland and Israel and advised him against releasing any more.

"I will not be making any further comment," he repeated over and over as reporters peppered him with questions.

Norris re-entered the race for the presidency last month amid widespread popular support. The 67-year-old's effervescent personality and strong human rights record, he spearheaded the campaign to decriminalise homosexuality in Ireland, have endeared him to many.

If elected, Norris would be the largely Catholic country's first gay president.

"I think he's brilliant. He's the only one I am voting for. He's funny, he's approachable. The media are picking on him," said Brenda, a 49-year-old civil servant, having a cigarette break in Dublin's city center.

McGuinness' insistence that he left the IRA in 1974 has prompted disbelief and a wave of criticism.

A senior government minister was quoted over the weekend as saying multinational companies would be "appalled" if McGuinness was elected president and Ireland's competitors for foreign investment would "not be slow to whisper about a terrorist" holding the office of president.

But the focus has switched back to Norris.

He confirmed a newspaper report on Wednesday that he received disability benefit from a Dublin university after he contracted hepatitis from contaminated water in 1994.

Norris said he was unable to continue lecturing due to his illness. He did, however, serve as a senator during that time.

Dubliners laughed off the disclosure.

"You need a bit of controversy. My vote is still for Norris," Mark Woods, a 37-year-old security guard, said.

(Editing by Louise Ireland)