Green MP Caroline Lucas is under investigation for a possible breach of parliamentary rules for offering a tour of the Commons in exchange for £150, as part of a fundraising drive. The Code of Conduct for MPs states members must not offer tours of the House in raffles or auctions. A complaint went to the Parliamentary Commissioner for Standards about the offer last year, the BBC understands. Caroline Lucas said she did not believe she had done anything wrong. The offer of a 30-minute "personal guided tour" of the Commons in exchange for a donation was part of a crowdfunding drive by Brighton and Hove Green Party during last year's general election campaign, to re-elect the Brighton Pavilion MP. It is understood the person who made the £150 donation visited the Commons with Caroline Lucas earlier this year. Members of the public can pay for a guided tour around the Houses of Parliament or UK residents can arrange one free of charge through their local MP. It is understood the Standards Commissioner began an investigation after receiving one complaint about the Green Party offer, but a subsequent complaint about the same issue was also received.