Donald Trump has repeatedly questioned U.S. intelligence agencies and the administration of President Barack Obama for stating Russia helped the president-elect win the 2016 election by hacking the Democratic Party. Most recently, while at his Mar-a-Lago estate in Florida, Trump turned away the ongoing controversy by saying it was “time for the country to move on to bigger and better things.”

However, some of the top intelligence and former foreign policy makers were now calling for an independent bipartisan commission to investigate possible “foreign interference” in the election, BuzzFeed News reported Wednesday.

The officials, which include former Secretary of State Madeline Albright, ex-Secretary of Defense Lion Panetta and former U.S. Ambassador to Russia Michael McFaul, each signed a letter in support of legislation House Democrats originally proposed last month.

“To understand fully and publicly what happened, how we were so vulnerable, and what we can do to protect our democracy in future elections, we the undersigned strongly encourage the Congress to create an independent, bipartisan commission to investigate efforts by the Russian Federation to influence or interfere with the U.S. presidential election in 2016,” the letter, obtained by Buzzfeed, read.

“Some have questioned whether the Russian government, despite the conclusion of 17 of our intelligence agencies, was really responsible for the hacks. Such doubts only reinforce why an independent, inquiry should occur outside of Congress,” the letter continued. “This inquiry should occur immediately. Anything less than a swift investigation will leave us vulnerable to another attack and, possibly worse, permit and normalize future interference.”

The legislation was first introduced by Rep. Eric Swalwell (D-Calif.), who sits on the House Permanent Select Committee on Intelligence, and Rep. Elijah Cummings (D-Md.), but Republicans in the House had yet to offer any such support.

The controversy over whether Russia, with President Vladimir Putin allegedly directing an operation dubbed “Grizzy Steppe” from the highest level, hacked emails from the Democratic National Committee and the campaign manager of former Democratic presidential nominee Hillary Clinton, John Podesta. Those messages were ultimately obtained by the WikiLeaks website. The site's founder, Julian Assange, has repeatedly denied the Russians as his source of Podesta's emails.

On Oct. 7 last year, the Director of National Intelligence, James R. Clapper, released a statement that said the U.S. Intelligence Community was “confident that the Russian Government directed the recent compromises of e-mails from U.S. persons and institutions, including U.S. political organizations.