AUGUSTA — Facing criticism from Democratic leaders in the Legislature, Gov. Paul LePage on Tuesday continued to defend his policy instructing department heads to communicate with lawmakers in writing.

That policy has largely kept department heads and other chief executive branch officials from showing up for questioning by lawmakers, which had been the normal practice for years.

Democrats have complained that having a back-and-forth in writing is cumbersome and time consuming, and have lamented that LePage would not allow officials to attend committee hearings in person.

Last week, LePage and top Democratic committee chairmen traded barbs about the policy. In a letter, the chairmen accused LePage of violating Maine’s Constitution, which requires the legislative and executive branches share information.

LePage repeated a refrain he has made many times before: The executive branch is a separate but equal form of government, and he is its chief. He will dictate how his employees spend their time.

In a three-page letter sent to the chairmen Tuesday, the governor said that asking his employees to sit in hearings, sometimes for hours, in case committee members needed them was a waste of time. He took a combative tone, making several fierce criticisms of legislative Democrats, who held the reins of power in the State House for decades until 2010, when the GOP won majorities that the party lost in 2012.

“Having become accustomed to one-party rule for so long, perhaps you believe the executive branch is still at your beck and call,” he wrote. “It must be frustrating to have to start conducting your work in a businesslike way.”

LePage added that every question submitted in writing by the lawmakers had been answered, and every request for information had been granted. He also said the policy creates additional transparency in government by creating a paper trail of communication between the two branches.

Over the weekend, Maine Sen. Linda Valentino, D-Saco, and House Majority Leader Seth Berry, D-Bowdoinham — who are each committee chairs — said the policy is backward and impractical.

“The governor has decided that communication between departments and committees will be in writing,” the duo wrote in an OpEd. “We live in a fast-moving digital age, but the governor may as well have us relying on the Pony Express. Committees are instructed by the governor to send written questions and receive written answers. Where is the opportunity for follow-up questions? For the dynamic conversations that take place in committees?”

LePage’s communication policy has been in place since this summer. On Tuesday, LePage said his employees must prioritize their work executing the law, rather than sitting in legislative hearings. He also accused the Democrats of feigning their outrage.

“Perhaps your frustration stems from your inability to berate members of my administration in person,” he wrote.

Valentino, who is chairwoman of the judiciary and workforce committees, said in a Tuesday interview that LePage’s argument doesn’t pass the straight-face test.

“If the governor really believes what he put in the letter, that this is an unproductive use of the executive’s time, why didn’t he institute this policy three years ago?” she said. “He let all the commissioners and department heads come before the committees for the two years Republicans were in control. Why did it take him all this time?”

LePage’s new communication policy was instituted in July, two months after the governor was barred from addressing the Appropriations Committee by its chairwoman, Sen. Dawn Hill, D-Cape Neddick. In silencing the governor, Hill said the committee had done what it needed to accomplish that day, and that she “wanted to end (the meeting) on a high note.”

In August, after barring several department heads from meeting with the Appropriations Committee, LePage connected his policy with Hill’s snub: “If the chief executive officer can’t speak, then I’m going to be a little tough on who goes up to speak,” he said.

Democratic committee heads were frustrated by LePage’s letter, and said that under the current policy, logjams in the Legislature are inevitable.

“Without the active participation from the administration, things are going to be slowed down,” said Sen. Emily Cain, D-Orono, who serves on Appropriations and chairs the Government Oversight Committee. “Without some resolution to this, it’s the people of Maine who are going to be caught in the middle.”