The Lobbying (Transparency) Bill - which would replace and extend many of the powers created in the 2014 legislation which created the Office of the Registrar of Consultant Lobbyists - was introduced to the House of Lords in May.
Brought to parliament by Labour peer and former trade union boss Lord Brooke of Alverthorpe, the act is seen as unlikely to pass into law. However, it gives an opportunity for the industry to gauge parliamentary opinion on the regulation of lobbying.
In the Lords on Friday, Lord Brookes accepted an amendment from Conservative former health secretary Lord Lansley, which would remove from the bill the provision for a statutory code of conduct for lobbyists.
"In my view there is a structure of voluntary codes that are more flexible, able to operate qualitatively and are therefore more appropriate to the task," Lansley said.
Lord Brooke maintained that the variety of different codes on offer - the PRCA's, the APPC's and the UK Lobbying Register's - "causes confusion and leads to a lack of clarity", but said he would accept Lansley's amendment "in the light of the issues that we have on timetabling and to move the business forward".
Cabinet Office spokeswoman Barones Chisholm of Owlpen welcomed Brooke's concession, but said it did not change the Government's position that it "believes that existing legislation achieves what it set out to do and that further regulation is not necessary".
PRCA director general Francis Ingham commented: "As Lord Lansley rightly argued, there is an existing structure of voluntary codes of conduct in the industry which are more appropriate and flexible than a statutory one. We have long argued that a statutory code of conduct risks undermining the transparent and ethical way in which the industry operates currently, and it is reassuring that peers have confirmed this view."
Ingham also went on to say that the PRCA remained "troubled" by other aspects of the bill, including one regarding financial disclosure.
Dates for the next parliamentary proceedings for the bill have yet to be announced.