The US Senate is due to consider a resolution on Thursday that would block President Donald Trump from taking further military action against Venezuela without congressional authorisation, and backers said the measure could pass in a close vote.

Days after US forces captured Venezuelan President Nicolas Maduro in a dramatic military raid in Caracas, senators will vote on the latest in a series of war powers measures introduced since the administration ramped up military pressure on the country with attacks on boats off its coast in September.

Republicans have blocked all of the measures, but the last vote was just 49-51, as two senators from Trump’s party joined Democrats in backing a resolution in November.

Administration officials had told lawmakers at that time that they did not plan regime change or strikes on Venezuelan territory.

After Maduro’s capture, some lawmakers have accused the administration of misleading Congress, including Democrats publicly and some Republicans behind the scenes.

“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 news conference ahead of the vote.

“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.

He did not identify the Republicans. Trump’s party holds a 53-47-seat majority in the Senate.

Senate passage would be a significant victory for the lawmakers who have been pushing the war powers issue.

But to become law, the resolution would have to pass the Republican-led House of Representatives and survive an expected Trump veto, which would require two-thirds majorities in both chambers.

The lawmakers acknowledged the hurdles, but said some Republicans may be wary of a prolonged and expensive campaign of regime change in Venezuela.

Trump on Wednesday said on his Truth Social website that he wanted the US military budget to increase to $1.5 trillion from $1 trillion.

Kaine noted that US forces have been striking Venezuelan boats for months, and mentioned Trump’s statement that the US would “run” Venezuela as well as the seizures of Venezuelan oil, saying: “This is not a surgical arrest operation by any stretch.”

The US Constitution requires any president to obtain Congress’s approval before launching a prolonged military operation.

Senators who oppose the war powers resolution say the seizure of Maduro is a law enforcement operation, not a military action. Maduro faces trial in a US court on drug and gun charges, to which he has pleaded not guilty. They also say that Trump is within his rights as commander-in-chief to launch limited military actions he feels are necessary for national security.