StP....an interesting question, which set me researching this morning !
In his Wiki entry, is the following ::
"On 21 July 2003, Archer was released on licence from Hollesley Bay after serving half of his sentence. Archer remained a peer, there being no legal provision through which it could be removed other than passing a new Act of Parliament.
He also retained membership of the House of Lords, which did not then have the power to expel members; however, Archer has not taken an active part in the proceedings of the House. Politically he is a non-affiliated member "
Not sure if that answers your question ! ....The Wiki entry makes for very intersting reading, as it leads you to wonder how he ever got into the Lords in the first place, given his track record :::
https://en.wikipedia.org/wiki/Jeffrey_Archer