A group of House conservatives will try to force a vote to repeal Obamacare without a replacement.

The House Freedom Caucus wants to revive a bill the House passed in 2015 that would repeal Obamacare after two years.

To get a vote, conservatives plan to introduce a discharge petition on the House floor. With 218 signatures, a majority of the House, Republican leaders would be forced to bring it up for a vote. But it's unlikely they will secure enough signatures.

The House this year passed a bill to repeal and replace parts of Obamacare using special rules that would require only 51 votes for passage in the Senate. Senate Republicans plan to bring up the House bill under those rules but will substitute either a different bill to repeal and replace Obamacare or the 2015 repeal bill that does not include a replacement.

The 2015 measure cleared Congress at that time but was vetoed by President Barack Obama.

As of Wednesday, Senate Republicans lacked the votes to pass either a straight repeal bill or one that includes a replacement for Obamacare.

House Freedom Caucus members said they are moving to force a House vote on the straight repeal bill to send a message to the Senate that they support passing such a measure, which they said would then force Republicans and Democrats to work together on a replacement.

"We understand that we have reached potentially an impasse," said House Freedom Caucus Chairman Mark Meadows, R-N.C., referring to the Senate. "I'm still hopeful they will come up with some kind of agreement. If not, we should put on President Trump's desk what we put on President Obama's desk."

House Republican leaders are unlikely to bring up a straight repeal bill that has not already passed the Senate this year because many Republicans are wary of repealing the bill now that it could actually be signed into law.