Pelosi said Friday that she will file a “discharge petition” to attempt to force the House to vote on the measure, which passed the Senate over the summer and would allow tax cuts to expire for those making more than $250,000 a year. Reid indicated in a floor speech opening the Senate’s business Tuesday that the petition will be filed today, and it was confirmed by Pelosi’s office.

The petition is used by the minority to force a floor vote when the House Speaker refuses to bring a bill forward. The mechanism is rarely used successfully — it takes 218 signatures to bring a bill forward. Even if all 192 Democrats sign on — and Reid indicated Tuesday that they will — a significant number of Republican defections would be needed.

Reid signaled Tuesday that Democrats will pressure Republicans to break ranks and support the effort.