Four Democratic Senators on Tuesday sent a letter to Majority Leader Harry Reid (D-Nev.) urging him to pursue reconciliation to pass their party’s health care reform bill.

Sens. Michael Bennet (Colo.) and Kirsten Gillibrand (N.Y.), both of whom are bracing for competitive primaries in their bids to win election to a full term this fall, joined Sens. Sherrod Brown (Ohio) and Jeff Merkley (Ore.) on the letter. The foursome also urges Reid to embrace the public insurance option, a measure excluded from the Senate bill that passed the chamber late last year. Neither Brown nor Merkley is up for re-election this year.

“We respectfully ask that you bring for a vote before the full Senate a public health insurance option under budget reconciliation rules,” the Senators said in their letter.

“Although we strongly support the important reforms made by the Senate-passed health reform package, including a strong public option would improve both its substance and the public’s perception of it,” the Senators said in the concluding paragraph of their letter. “The Senate has an obligation to reform our unworkable health insurance market — both to reduce costs and to give consumers more choices. A strong public option is the best way to deliver on both of these goals, and we urge its consideration under reconciliation rules.”

Senate Democratic health care staff has been quietly drafting a reconciliation package, which would allow Democrats to pass certain aspects of the overhaul with 51 votes. But the Senate leadership has not made a final decision on whether to move forward with this strategy.