A Fine Gael TD couriered a letter, written on his own Dáil headed paper, to a small business owner informing her she would be summonsed to an Employment Appeals Tribunal case in which he is involved.
Cavan-Monaghan deputy Seán Conlan sent the letter to the owner of a shop in Castleblayney, Co Monaghan, where his former Dáil secretarial assistant is employed.
Cathy Shevlin, the former secretarial assistant to Mr Conlan, has taken an unfair dismissal case against him.
It was initially heard before the tribunal in Dublin in October.
The case, which is due back before the tribunal on Thursday, is expected to conclude over two days of hearings.
Mr Conlan denies he harassed and bullied Ms Shevlin, and alleges she shared sensitive tally information with potential political rivals.
The TD did not return calls or requests for comment last night.
His solicitor, Kevin O’Higgins, also did not respond to inquiries.
Former lord mayor of Dublin Oisín Quinn is Mr Conlan’s barrister in the case.
Mr Conlan is a member of the prominent “five-a-side” group of Fine Gael TDs and previously criticised Taoiseach Enda Kenny over the controversy involving the nomination of John McNulty to run for the Seanad.
The letter from Mr Conlan in relation to the tribunal proceedings is headed: “Re: Cathy Shevlin-v-Seán Conlan”.
It starts “Dear ”, before stating: “I refer to the above case which is presently before the Employment Appeals Tribunal.
“An application was made before the Employment Appeals Tribunal yesterday the 28th of November 2014 to apply for a summons compelling you to attend in respect of the above matter.
“The tribunal granted the application and made an order summonsing you to attend the tribunal which is located at Davitt House, 65a Adelaide Road, Dublin 2 on Thursday the 4th and Friday the 5th of December 2014 at 10am.
“My legal team will be calling on you to give evidence at the tribunal.
“Please bring with you any relevant documentation in relation to the above.”