WASHINGTON (Reuters) - The top Democrat on the U.S. Senate Intelligence Committee said on Tuesday he would support President Donald Trump’s nominee to be CIA director, Gina Haspel, all but ensuring her confirmation as the first woman to lead the spy agency.

Senator Mark Warner said it had been a “difficult decision,” but cited Haspel’s 33-year career and support from the CIA workforce and intelligence veterans.

“Most importantly, I believe she is someone who can and will stand up to the President if ordered to do something illegal or immoral – like a return to torture,” Warner said in a statement.

In a letter to Warner dated Monday, Haspel said the CIA should not have undertaken a past harsh interrogation program, which has been a focus of debate over her confirmation.

The Senate Intelligence Committee is due to vote on Wednesday on whether to approve Haspel. With Warner’s support, she is expected to have the backing of all eight committee Republicans and at least two of the seven Democrats.

Despite criticism - including from Republican Senators Rand Paul and John McCain - because of past ties to the CIA’s former rendition, detention and interrogation activities, Haspel is expected to be confirmed by the full Senate next week.

At least four other Democrats, all up for re-election in states Trump won in 2016, also support Haspel. Democratic Senators Heidi Heitkamp of North Dakota and Bill Nelson of Florida announced their backing on Tuesday.

Haspel pledged at her confirmation hearing that she would never restart the program, put in place after the Sept. 11 attacks, but did not go as far as saying it should not have been started.

Haspel in 2002 served as station chief in Thailand, where the CIA conducted interrogations at a secret prison using methods including waterboarding, widely viewed as torture.

Three years later, she drafted a cable ordering the destruction of videotapes of those interrogations.

“While I won’t condemn those that made those hard calls, and I have noted the valuable intelligence collected, the program ultimately did damage to our officers and our standing in the world,” Haspel said in the letter, which did not address the videotapes.

“With the benefit of hindsight and my experience as a senior Agency leader, the enhanced interrogation program is not one the CIA should have undertaken. The United States must be an example to the rest of the world, and I support that,” Haspel said.