A woman has told a news conference how Republican presidential hopeful Herman Cain groped her when she asked for his help finding work in the 1990s.Sharon Bialek, a former employee of a restaurant lobby group, said Mr Cain had reached up her skirt and pulled her head towards his crotch.Hers is the fourth allegation of sexual misconduct to emerge against Mr Cain.The Cain campaign immediately issued a denial: \"All allegations of harassment against Mr Cain are false.\"Mr Cain, a former pizza magnate, is a leading contender for the Republican nomination to take on President Barack Obama in 2012.Washington news website Politico reported a week ago that at least two women had complained of sexual harassment while he was head of a lobby group, the National Restaurant Association, in the 1990s.A third woman came forward days later, accusing Mr Cain of inappropriate behaviour at around the same time.Ms Bialek is the first of the accusers to speak publicly.She told a news conference in New York that she had first met Mr Cain when she was seated next to him during a meal at the association\'s annual convention. She described him as \"warm and attentive\" towards both her and her boyfriend at the dinner.A month later, she was sacked from her job as a manager at the association\'s education foundation.Ms Bialek\'s boyfriend suggested that she should contact Mr Cain to help her find other employment.She said that Mr Cain had agreed to meet her in Washington DC in mid-July 1997, where he upgraded her hotel room.The alleged groping incident occurred after they had dinner and Ms Bialek asked Mr Cain if he could help find her work at the state-level of the association, she told reporters.\"Instead of going into the offices he suddenly reached over and he put his hand on my leg, under my skirt toward my genitals,\" she said.\"He also pushed my head toward his crotch.\"Ms Bialek appeared to struggle to maintain her composure as she told journalists that she had asked Mr Cain what he was doing, to which he allegedly replied: \"You want a job, don\'t you?\"She was flanked at the Manhattan news conference by her lawyer, Gloria Allred, who has represented several high-profile clients, including an alleged mistress of golfer Tiger Woods.The lawyer said she had two sworn statements from Ms Bialek\'s then boyfriend, as well as a longstanding friend, who said she had told them about Mr Cain\'s alleged behaviour shortly afterwards.His campaign spokesman JD Gordon called Ms Allred a \"major donor\" to Democrats, and blamed the lawyer for bringing \"false accusations\" against Mr Cain \"just as the country finally begins to refocus on our crippling $15 trillion national debt\".Federal election commission reports show that Ms Allred gave $1,000 (£624) to Hillary Rodham Clinton and $2,300 to Barack Obama during the 2008 presidential campaign.Ms Allred said that if all the allegations by other women are true, \"then I, for one, am disgusted at Mr Cain\'s serial sexual harassment of women\".Mr Cain acknowledged last week that one of his accusers received a financial settlement from the National Restaurant Association.That woman - who reportedly won a $45,000 (£28,000) payout - issued a statement on Friday through her lawyer saying that Mr Cain had made a \"series of inappropriate behaviours and unwanted advances\".But despite being released from a confidentiality clause in the settlement, she said she wished to remain anonymous.