AUGUSTA — The longstanding feud between Democratic Attorney General Janet Mills and Republican Gov. Paul LePage has escalated with Mills warning the administration to stop using executive branch attorneys to handle legal matters that should be her office’s responsibility and with LePage’s legal counsel telling Mills that she and her staff can’t be trusted.

The conflict between Mills and LePage traces back years but has intensified in recent months with Mills repeatedly informing the administration that state agencies cannot legally hire attorneys outside the attorney general’s office without her approval.

“A person who happens to have a law degree [and works for state government] may give policy and strategy advice, but in no case should that attorney profess to give legal advice,” Mills wrote. “The administration is free to call upon this office and draw upon our experience for the history and interpretation of any statute or fact scenario, as we have given such advice to administrations of every stripe over many years. That is the job and the obligation of this office.”

In a sharply worded response, Montgomery — whose nomination to a judgeship by LePage in December awaits legislative confirmation votes — attacked Mills directly.

“I have said to you directly and specifically on more than one occasion that this administration does not trust you — and by extension, your office — to advise or represent it with non-partisan, professional legal judgment,” Montgomery wrote in a Jan. 14 letter to Mills. “This distrust is due in large part to your long history of taking strident and public stands against the policy decisions of the administration.”

This conflict began to reach a boil in 2014 when Mills refused to represent LePage in court proceedings over two of his initiatives that she had previously deemed unconstitutional: A dispute between the state and federal government about whether Maine could drop some 19- and 20-year-olds from its Medicaid rolls, and a lawsuit filed against the state by Portland, Westbrook and the Maine Municipal Association over LePage’s attempt to change state policy on providing General Assistance to some immigrants.

Mills allowed LePage to hire his own attorney in both cases. A federal appeals court ruled against the state in November 2014 in the Medicaid suit and the U.S. Supreme Court later rejected it. The failed suit cost Maine taxpayers $108,000 in legal fees paid to the private, Portland-based law firm Roach, Hewitt, Ruprecht, Sanchez & Bischoff.

The administration paid the same firm about $100,000 in fees in the General Assistance suit, which went largely in the administration’s favor in June 2015 when the Maine Supreme Judicial Court ruled that the state doesn’t have to reimburse municipalities for General Assistance payments to refugees and asylum seekers who are not eligible for those benefits under federal guidelines.

On Jan. 7, Mills sent a letter to department heads and directors in the Department of Health and Human Services, notifying them that Jane Gregory had been appointed lead attorney for a team of attorneys in her office for all health and human services matters.

“Reliance on legal advice other than from this office could result in liability on the part of an employee, a supervisor or the department itself, which would not be protected by the Maine Tort Claims Act or by qualified immunity under federal law,” Mills wrote.

Mills followed that letter with the Jan. 8 letter to Montgomery in which Mills established the following parameters for the hiring of attorneys:

— No position for a state government job should be advertised as requiring a law degree without the approval of the attorney general.

— No position should describe “legal counsel,” “legal advice” or otherwise include legal expertise without the approval of the attorney general.

— No person should be relied upon in any way for legal expertise without approval of the attorney general.

Montgomery responded that Mills circumvented her and DHHS Commissioner Mary Mayhew when Mills issued those directives.

“I disagree with most, if not all, of those parameters,” wrote Montgomery, who also accused Mills of “resistance, partisanship and downright hostility.”

Montgomery wrote that all executive branch employees have been instructed to “refrain from acting in a legal representational capacity” and adhere to the provisions of the state’s Administrative Procedures Act.

“That said, while you can force compliance with the terms of the statute, you cannot force the executive branch agencies to trust you, or by extension, the attorneys who report to you,” Montgomery wrote.

On Friday, Jan. 22, Mills responded with another letter.

“Let me get right to the point,” Mills wrote. “The administration is violating the law by hiring individuals who hold themselves out as attorneys for the state and by permitting them to provide legal advice. … The job of a lawyer does not begin at the courthouse steps. The job of a lawyer begins before an action is taken, when litigation can best be avoided.”

Mills signaled that she is ready to take action against the executive branch unless it modifies certain job descriptions to make it clear that those employees will not provide legal advice.

“Kindly advise whether it will be necessary to take other action to enforce the clear provisions of the statute or whether the administration will modify these positions in order to comply with the law,” Mills wrote. “By copy of this letter I am again putting the lawyers in question on notice that holding themselves out as ‘counsel’ or providing legal services without our approval is a violation of statute.”

Mills declined to comment on the situation Sunday morning, and the LePage administration did not respond immediately to a request for comment.