The U.S. Senate advanced a resolution on Thursday that would bar President Donald Trump from taking further military action against Venezuela without congressional authorisation, paving the way for further consideration in the 100-member chamber.

The vote on a procedural measure to advance the war powers resolution was 52 to 47, as five of Trump’s fellow Republicans voted with every Democrat in favour of moving ahead. One Republican senator did not vote.

The vote took place days after U.S. forces captured Venezuelan President Nicolas Maduro in a dramatic military raid in Caracas on Saturday, and marked a shift in the 100-member chamber.

Trump’s Republicans had blocked two previous attempts to advance similar resolutions in the Senate last year, as the administration ramped up military pressure on Venezuela with attacks on boats in the southern Caribbean and eastern Pacific.

However, the vote blocking the last resolution in November was only 51-49, just after top Trump advisors told lawmakers they did not plan to change the government or conduct strikes on Venezuelan territory.

After Maduro’s capture, some lawmakers accused the administration of misleading Congress, including Democrats publicly and some Republicans behind the scenes. Maduro’s capture and Trump’s rhetoric have also raised concerns that he might launch military action to capture Greenland, an Arctic island that is a territory of Denmark.

“I spoke to at least two Republicans today who did not vote for this resolution previously who are thinking about it,” Senator Rand Paul, a Kentucky Republican who is co-sponsoring the resolution, told a press conference on Wednesday.

“I can’t guarantee you how they vote, but at least two are thinking about it, and some of them are talking publicly about their misgivings over this,” Paul said, speaking beside Democratic Senator Tim Kaine of Virginia, another leader of the resolution.

Both senators are members of the Foreign Relations Committee.

The five Republicans who voted on Thursday to move ahead were Paul, Susan Collins of Maine, Josh Hawley of Missouri, Lisa Murkowski of Alaska and Todd Young of Indiana. Trump’s party holds a 53-47 majority in the Senate.

HURDLES AHEAD

Thursday’s vote setting the stage for further consideration in the Senate was a significant victory for lawmakers who have been arguing that Congress, not the president, should declare war, as spelled out in the Constitution.

However, the measure faces steep hurdles before going into effect.

Even if it passes the Senate, to become law, the resolution must also pass the Republican-led House of Representatives and override an expected Trump veto, which would require two-thirds majorities in both chambers.

The bill’s backers have acknowledged the hurdles, but said Republicans may be wary of a possible prolonged and expensive campaign of government change in Venezuela, as the U.S. faces steep budget deficits.

Trump on Wednesday said he wanted U.S. military spending to increase to $1.5 trillion from $1 trillion.

Kaine noted that U.S. forces have been striking Venezuelan boats for months, and mentioned Trump’s statement that the U.S. would “run” Venezuela as well as the seizures of Venezuelan oil.

“This is not a surgical arrest operation by any stretch,” Kaine said.

Senators who opposed the war powers resolution said Maduro’s seizure was a law enforcement operation, not a military action. Maduro faces trial in a U.S. court on drug and gun charges, to which he has pleaded not guilty.

The senators also say that Trump is within his rights as commander-in-chief to launch limited military actions he feels are necessary for national security.

“The purpose of this resolution is to slap the president in the face. It will do nothing that it purports to do because it can’t stop something that isn’t going on right now,” Senator Jim Risch of Idaho, the Republican chairman of the foreign relations panel, said in a Senate speech before the vote.