WILLIAMSBURG, Va. — Even as the Democratic Congressional Campaign Committee revealed Thursday it has $35.1 million in the bank, Chairman Chris Van Hollen (Md.) issued a warning to lawmakers against becoming slothful in their fundraising efforts.

Estimating that as many as 70 House seats could be up for grabs in the November elections, Van Hollen said that competition presents “a big challenge resource-wise.”

“In order to support the strategy we’ve got now we’re going to need to raise more than last time,” Van Hollen said Thursday, after addressing the Democratic Caucus at its annual retreat at the Kingsmill Resort here.

According to Van Hollen, the DCCC recorded $74 million in expenditures in the 2006 cycle.

In particular, Van Hollen said he warned Members not to take the DCCC’s fundraising lead over the National Republican Congressional Committee — which reported $2.3 million in cash on hand through Nov. 30 — for granted, and to be prepared for well-funded attacks from conservative 527 organizations.

“The universe of players here goes way beyond the DCCC and the Republican committee,” he said.

Despite an otherwise upbeat presentation to Members, Van Hollen remained hesitant about forecasting gains in the November elections.

“I’d be very cautious about predicting any kind of second wave,” he said.

House Majority Leader Steny Hoyer (D-Md.) was less circumspect Thursday, however, asserting that Democrats could pick up as many as 15 seats in the November elections.

“We may be in a position to win a net 10 to 15 seats. … I think that is very possible,” Hoyer said.