The first poll on the special House election to replace new Sen. Kirsten Gillibrand (D-N.Y.) shows the Republican nominee, state Assembly Minority Leader Jim Tedisco, with a wide lead over the Democrat, venture capitalist Scott Murphy.

But by the Republican pollster’s own account, the race is just getting started and is certain to tighten.

The poll, conducted Tuesday and Wednesday by Public Opinion Strategies for Tedisco, found the veteran legislator leading Murphy, 50 percent to 29 percent. The survey of 400 voters had a 4.9-point margin of error.

In a memo, pollster Patrick Lanne noted that Murphy was only known by 17 percent of those surveyed and said the Democrat’s numbers are certain to go up as he and party leaders spend money on the race. He warned that Democrats are certain to spend heavily to drive up Tedisco’s negatives.

But Lanne also said Tedisco, who has been in the Assembly since 1983 and has been in public office since the 1970s, begins the contest with solid fundamentals. Fifty-one percent of those surveyed gave Tedisco favorable marks, while only 13 percent viewed him unfavorably.

“Jim Tedisco’s deep roots in the district and his proven track record of advocacy for upstate New York establishes him as the clear front-runner in this campaign,” Lanne wrote.

No special election date has been set to replace Gillibrand, who was appointed to the Senate two weeks ago. Republicans are accusing Gov. David Paterson (D) of dragging his feet on setting the special election, to give Murphy more time to raise his profile.