Updated: 11:54 a.m.

Senate Majority Leader Harry Reid (Nev.) and Democratic Conference Vice Chairman Charles Schumer (N.Y.) are moving to assure wavering House Democrats that the Senate will take up new campaign finance legislation in time for it to take effect for the November elections.

According to a Democratic leadership aide, Reid and Schumer are preparing to send a letter Tuesday to Speaker Nancy Pelosi (D-Calif.) and House Administration Chairman Robert Brady (D-Pa.) declaring their commitment to Senate passage of the legislation, which would counteract a recent Supreme Court decision that overturned some existing campaign finance rules.

The DISCLOSE Act would reinstate some restrictions on corporate and special interest spending in elections, which the court ruling invalidated. The bill, which has some Republican support in the House, appeared on its way to passage before several nervous moderate and conservative lawmakers dropped their support for the bill. Among their reasons for walking away, these Democrats expressed a fear that they would be forced to vote on the issue, only to see the Senate fail to take it up.

The letter from Reid and Schumer appears targeted at them, according to a copy provided to Roll Call.

“We commit to working tirelessly for Senate consideration of the House-passed bill so it can be signed by the President in time to take effect for the 2010 elections,” the letter reads.

According to the letter, companion legislation to the DISCLOSE Act has 50 co-sponsors in the Senate. It remains unclear whether Democratic leaders in the Senate will be able assemble the 60 votes needed to overcome any filibusters or procedural objections that might arise should the bill hit the floor.

Rep. Chris Van Hollen (Md.), chairman of the Democratic Congressional Campaign Committee and the lead sponsor of the act, issued a statement Tuesday urging his House colleagues to act quickly on the legislation.

“Today’s letter from Majority Leader Reid and Senator Schumer makes clear that the Senate is committed to taking up and passing the DISCLOSE Act in short order, and I urge my colleagues in the House to take the first step and pass the measure this week,” Van Hollen said in the statement.