Acting Prime Minister Ehud Olmert's party, the clear frontrunner in a March 28 election, gained more voter support after a dramatic West Bank prison raid, according to a poll published Thursday. The raid, in which IDF troops seized the leader of a radical PLO faction, had wide backing in Israel, but some questioned its pre-election timing. Olmert has flatly rejected allegations he ordered the raid to win the support of hard-line voters. Olmert's centrist Kadima Party had recently dropped in opinion polls to under 40 of 120 parliamentary seats, still far ahead of its closest rivals, but raising speculation that a coalition headed by Olmert would not be strong enough to implement his vision of West Bank withdrawals. Surveys published Thursday showed Kadima gaining ground. Some pollsters and political analysts attributed the rise to Tuesday's prison raid, during which the army spirited away Ahmed Saadat, the mastermind of the 2001 assassination of an Israeli Cabinet minister. In a poll conducted Wednesday by the independent Geocartography Institute, Kadima rose to between 42-43 seats, up from 38 last week, said Avi Degani, head of the polling agency. However, Kadima's rise cannot necessarily be attributed to the Jericho prison raid, because Geocartography had similar results in a survey conducted Monday - a day before the operation, Degani said. Degani said 10 percent of the voters were still undecided, and another 30 percent were not fully committed to one party yet, making up a large group that could change the balance on election day. Degani's poll of 500 people taken Wednesday had an error margin of 4.3 percentage points. Other polls also had Kadima rising, but not passing the 40-seat mark In a Dahaf survey published in Yediot Aharonoth, Kadima won 39 of 120 parliamentary seats, up two from last week's survey. The left-center Labor Party lost ground, garnering 19 seats, one less than in a previous Dahaf poll. The hard-line Likud Party rose slightly in the poll, bringing in 15 seats, up one from the previous poll. The Dahaf poll, taken Wednesday among 1,002 eligible voters, had an error margin of 4.4 percentage points. A Teleseker survey published Thursday in the Maariv daily had Kadima gaining one seat, to 39. Labor also strengthened slightly, grabbing 20 seats, compared to last week's 19. Likud dropped to 15 seats from a previous high of 17. The poll, taken Tuesday among 500 eligible voters, had an error margin of 4.4 percentage points.