Royal Bank of Scotland Insurance (RBSI) has for the first time given permission to one of its corporate partners to appear on an aggregator site other than

But the move could frustrate RBSI’s other corporate partners which have not been given a similar permission.

Lloyds TSB, whose motor insurance is underwritten by RBS-owned Churchill, is understood to have been in discussions with since October about becoming listed on the price comparison site.

Moneysupermarket director of insurance Richard Mason said the hope was to have Lloyds TSB on its site by February.

Mason said he predicted the move to grant only Lloyds TSB the freedom to appear on the sites might cause conflict with RBSI’s other corporate partners also keen on garnering a competitive edge.

Mason said: “We’ve had chats with the others and they are keen to be on aggregator sites and we were quite surprised only Lloyds TSB was given permission.”

RBSI also underwrites insurance for companies such as Virgin Money, Privilege and Prudential. The company’s in-house brands NIG and Churchill have also not appeared on other price comparison websites.

A TSB spokesperson said: “We would never comment on speculation about plans for the future”.

RBSI, Privilege and Prudential declined to comment. Virgin Money was unavailable for comment.