A full 60 Democrats have now pledged to vote for healthcare reform only if it contains a public option.

In a letter to Health and Human Services Secretary Kathleen SebeliusKathleen SebeliusThe House needs to help patients from being victimized by antiquated technology Obama cabinet official: Clinton White House doubled down on 'abusive behavior' John Roberts has tough job of keeping faith in Supreme Court MORE (obtained by Firedoglake), the Congressional Progressive Caucus took issue with Sebelius's recent statement that a public plan was "not the essential element" of healthcare reform, and pledged 60 votes against final passage unless a public plan is included:
To take the public option off the table would be a grave error; passage in the House of Representatives depends upon inclusion of it.

We have attached, for your review, a letter from 60 Members of Congress who are firm in their position that any legislation that moves forward through both chambers, and into a final proposal for the President's signature, MUST contain a public option.

A previous, similar pledge by the progressive caucus included 50 members, so support for the public plan seems to be growing among House liberals.

Centrists have speculated that House liberals may demand a vote on the public option when a bill first goes through the House, but would eventually accept a conference committee compromise that lacked a goverment plan. This letter seems to suggest that's not the case.