However, by posting the letter, Regan has been found to have broken the rules.
The standards committee found that she was in breach of section 9.1 of the code, which says MSPs “must not disclose, communicate or discuss any complaint or intention to make a complaint to or with members of the press or other media” before the end of the process.
Regan claimed in her defence that she did not make a complaint, believing that was “better left to members of the public”, and that she had no intention of making a complaint.
Committee convener and Labour MSP Martin Whitfield dismissed that argument.
He pointed out that Regan’s letter included statements such as “formally raising concerns” and “respectfully request that this matter be considered by the relevant parliamentary authorities”.
The committee also highlighted emails from Regan to Johnstone referencing a “formal complaint”.