Transcript for House Democrats prepare to vote on overturning Trump's emergency declaration

I'm John Parkinson at the capitol and you're watching ABC news lives. House Democrats have begun moving legislation to terminate president trumps national emergency declaration. To obtain more money for the border wall it's the opening salvo in a battle that is expected to drag on into the next presidential campaign. Trump declared a national emergency at the southern border February 15 taking executive action to obtain more money for his border wall. We do have an emergency we have an emergency of people pouring into a country that we don't want. Criminals smugglers. We have drugs pouring into our country we can't have it Democrats still are buying them. And then orders technology is not yeah. The resolution to terminate the national emergency is expected to pass the house Tuesday before the senate considers the measure in the coming weeks. If the measure passes both chambers of congress. It sets up the president's first potential veto and so far there doesn't seem to be enough support on Capitol Hill to override the president's veto. On Capitol Hill for ABC news live I'm John Parkinson.

This transcript has been automatically generated and may not be 100% accurate.