The Director of a Scottish public affairs company has written to the Speaker of the House of Commons to complain about a speech made by Fife MP Thomas Docherty.
Mark Cummings, of Invicta, is demanding a public apology from the Dunfermline and West Fife Labour MP.
He said Mr Docherty made the comments last Friday during a debate on the second reading of the Commercial Lobbyists (Registration and Code of Conduct) Bill.
A statement has been issued by lawyer Campbell Deane on behalf of Mr Cummings denying the claims.
Mr Cummings has written to the MP challenging him to repeat the accusations without the protection of parliamentary privilege.
He said: “I am absolutely appalled at the conduct of Mr Docherty.
“To attack me personally and my company in this way without warning and under the cloak of parliamentary privilege is a serious abuse of his power as an MP.”
Mr Docherty said free speech in the Commons had existed for more than 300 years to ensure MPs could explore hypocrisy and immoral behaviour without fear of bullying, intimidation or reprisals.
“Many will find it ironic in light of the issues raised that Mr Cumming now appears to be using such tactics to curtail these freedoms.”