Rep. Jason Chaffetz, the chairman of the House Oversight and Government Reform Committee. REUTERS/Jonathan Ernst Rep. Jason Chaffetz, chairman of the House oversight committee, announced on Thursday that he'll be leaving office on June 30, 18 months before the end of his congressional term.

In a statement, Chaffetz said that he had always meant for his time in Congress to be temporary, and that he's looking forward to spending more time with his family.

"The reality of spending more than 1,500 nights away from my family over eight years hit me harder than it had before," he wrote.

Chaffetz has faced criticism recently for his role in investigating President Donald Trump and his administration. In February, he met a packed townhall in his Utah district, filled with constituents chanting, "do your job."

On Tuesday, Chaffetz demanded that the FBI turn over all documents in its possession concerning communications between Trump and James Comey, whom Trump fired last week as FBI director. Chaffetz also asked Comey to testify before the House next week.

This came after The New York Times reported that Comey wrote memos detailing his interactions with the president. In one of these memos, Comey wrote that Trump suggested he drop the agency's investigation into Trump's former national security adviser, Michael Flynn.

On Wednesday evening, shortly after the Justice Department's announcement that it had selected former FBI Director Robert Mueller as a special counsel to oversee investigations into possible ties between the Trump campaign and Russia, Chaffetz told Fox News that he was not convinced a special counsel was necessary.

"I have not seen any evidence of actual collusion," Chaffetz said. "Where is the actual crime that they think they need a special prosecutor to prosecute? I just haven't seen it."

Chaffetz also expressed skepticism about the memos detailed by The Times.

"I'm not even sure that these memos even exist," Chaffetz said, adding: "You can't run an investigation on anonymous sources in The New York Times. That's just not conclusive evidence."

Chaffetz announced in April that he would not seek reelection in 2018. The Washingtonian reported on Monday that Chaffetz may join Fox News after leaving office.