A plan for a presidential primary in June for Democrats is on the ropes with a deadline to get it ready approached fast.

About 18 democratic lawmakers called a press conference Tuesday afternoon to announce they won't support a primary that Barack Obama hasn't signed off on. His campaign has not agreed to legislation that would set up a June 3 primary paid for from a public fund with private donations.

Those lawmakers also say they think it's wrong to exclude Democrats who voted in the Republican primary in January, assuming their vote for a Democrat would not count. They estimate there are about 100,000 of them.

Lawmakers continue to say they are confidant the delegates would be seated at the Democratic Convention in Denver, though it is unclear how or why they say that.