Which former MP was this?

A former MP sent this lovely message out of the blue to Chris Finlayson after his valedictory:

Date: Tuesday, 18 Dec 2018, 19:40

To: Hon Christopher Finlayson 

Subject: farewell

And (to resort to the vernacular of your basic origins):

Fucking good riddance – rat..

The reply from Mr Finlayson was:

From: HonChristopher Finlayson

Date: Tuesday, 18 Dec 2018, 20:32
Subject: RE: farewell
 
Dear Mr xxxxxxx
 
I am very worried that a lunatic has broken into your system and is sending demented e mails in your name. I suggest you contact the Police.
 
Yours sincerely
 
Chris Finlayson