asked Her Majesty's Government:With reference to their Answer of 5th June [
Official Report, Vol. 508, No. 94; col. 716] to Lord Grimond's question asking who is entitled to be called "Right Honourable", (i) why no women were listed and (ii) why in lists of Ministers, etc., only those Peers who are Privy Counsellors have the prefix "Rt. Hon.".
The Minister of State, Home Office (Earl Ferrers)
Essentially, this is a question of practice usage and custom. I should like, however, to correct and amplify the Answer to the Question of the noble Lord, Lord Grimond, to which this Question refers.The Lord Mayors of Belfast and Cardiff and the Lord Provost of Glasgow are entitled to the style "Right Honourable" by express grant of the Sovereign. The style is also taken by Privy Counsellors, Peers below the rank of Marquess (which includes ladies who are Peers in their own right), the Lord Mayors of London and York and the Lord Provost of Edinburgh by ancient prescriptive usage.
For official purposes, the style is omitted in many circumstances, owing to the need for brevity, clarity or informality, as the occasion dictates. For example, the style is omitted in lists of Ministers for Peers who fall below the rank of Marquess and who are not Privy Counsellors in order to distinguish them from Peers who are Privy Counsellors. The style is commonly used for formal social purposes by Peers below the rank of Marquess and Peeresses below the rank of Marchioness.