Are Sam Katz, bidding to become Philadelphia's first Republican mayor in a half-century, and Democrat John Street locked in a dead heat with the election just 10 weeks away?

Or is Street, the former City Council president, entering the fall race with a lead of landslide proportions - some 25 percentage points.

It all depends on which candidate's poll you choose to believe.

In a clear sign that the two major-party candidates are jockeying for position as the traditional Labor Day start of campaigning draws near, aides to Katz and Street floated radically different poll numbers to the media yesterday.

It all started when the Katz campaign released a three-page memo from its polling consultant, John McLaughlin & Associates, saying that a survey of 600 likely fall voters found a statistical dead heat, with 42.2 percent saying they back Street and 40.8 percent for Katz, with 17 percent undecided.

The pollster, noting that Katz had trailed by 5 percentage points in a somewhat larger sample from late June, wrote that "at this stage of the election, Sam Katz clearly has the momentum to not only seriously challenge John Street, but to win the November election."

"This poll ought to be in Gourmet magazine because the numbers are cooked," countered a Street campaign spokeswoman, Caroline Brobeil. She said the second of two polls done this summer for the Street campaign by Lester and Associates shows the Democrat ahead by a sizable 55 percent to 32 percent.

The Street campaign then released a two-page memo from pollster Ronald Lester on its early August survey of 600 voters. "Street benefits form having a track record as City Council president most voters are comfortable with," he wrote, adding that "Street's voter support is also very strong, and Katz's voter support is weak."

Why are the poll numbers so important in an election 70 days away?

While Katz says he plans to win in November on issues like wanting deeper wage-tax cuts than Street and on school vouchers, which Street opposes, the Republican and his aides also fear that few will pay much attention if voters and the media think the race is another Democratic blowout.

The racket over numbers also comes on the eve of some critical behind-the-scenes work by both campaigns to gain the backing of defeated Democrat John White Jr. and his key allies.

Katz is meeting in private with White and some supporters on Thursday, while Street - who is taking a virtual vacation this week - will talk to the same group next week.