House Democrats have canceled plans for nearly $1 million in advertising on two House races in New Hampshire, several weeks after signaling they would mount a strong challenge against both of the state's incumbent Republican lawmakers.

Less than six weeks before the Nov. 2 election, Democrats also decided to delay advertising in a Florida race where the party's candidate recently withdrew, citing health reasons.

The developments, disclosed in public records and confirmed by a party spokesman, come as Democratic Leader Nancy Pelosi (search) publicly has guaranteed her party will win its long-shot attempt to gain control of the House from Republicans.

Greg Speed, a spokesman for the Democratic Congressional Campaign Committee (search), stressed that the change of plans in New Hampshire did not preclude advertising there later this fall. Instead, he said it reflected an unusual demand from a television station for advance payment for all five weeks of planned advertising.

"This is the only market in the country where we're being asked to pay for a month and a half of television up front," he said. "There's absolutely nothing to keep us from going back in the very near future and we're strongly considering doing that."

As for Florida, Speed called that race a "very fluid situation."

"We're confident that we'll have a candidate to run against Clay Shaw," he said referring to the veteran Republican lawmaker the party long has sought to defeat. "Right now we do not due to Jim Stork leaving the race for health reasons. And once the candidate's in the race we'll proceed from there."

Speed did not flatly commit to the party advertising in either state, and Republicans seized on the change in plans as evidence of political difficulty.

"This is clear evidence the Democrats are either having money problems or are giving up on races they had previously targeted," said Carl Forti, a spokesman for the National Republican Congressional Committee.

Democrats must gain 12 seats this fall to end a decade in the minority, and have struggled all year to make enough seats competitive to have a strong chance of winning. No more than 40 seats appear competitive at this point in the campaign, and many are already held by Democrats, including several in Texas.

Parties often signal their political priorities by allocating the advertising money they intend to spend independent of candidates. So far, both parties are running commercials in four districts, a number expected to increase significantly in the next two weeks.

Democrats are advertising in two races in Washington, one in New Mexico and one in New York.

Republicans are in one seat each in Washington, California, Colorado and Texas.

For their part, Republicans show signs of attempting to expand the number of Democratic-held seats that are competitive, hoping either to win one or two or perhaps merely force Democrats to spend money defending them.

In California, for example, the GOP recently began airing a commercial touting Roy Ashburn, a candidate for a Fresno-area district. Records on file with the Federal Election Commission also indicate they plan to advertise in a district on Long Island, N.Y., held by Democrat Tim Bishop.

At the same time, Republicans reflected concern in Nebraska recently when they reserved advertising time in the Omaha area, which reaches into two GOP-held districts not generally mentioned as competitive.

In New Hampshire, Democrats filed papers this month to reserve five weeks of television time at a cost of $944,000. They said at the time the money was aimed at helping Paul Hodes, running against Rep. Charles Bass; and Justin Nadeau, challenging first-term Rep. Jeb Bradley.

In Florida, the Democrats had planned to run its first ads the week of Oct. 5. That week's commercials have been withdrawn.

Faced with a candidate vacancy, party officials have been in discussions with Rep. Peter Deutsch, who has expressed interest in running for the seat. Deutsch ran for the Senate this year, but lost in the primary.