The Scottish Council for Voluntary Organisations (SCVO), the national charity umbrella group leading the fight against plans to regulate lobbying at Holyrood, is under fire for trying to charge its own members for tips on how to lobby MSPs.

The SCVO, a strident critic of proposals unveiled by Labour MSP Neil Findlay for a statutory register for lobbyists, last week publicised a course on "lobbying tools", at a cost of up to £230 a ticket.

Findlay's proposed legislation would compel public-affairs specialists to list their meetings with MSPs and ministers, and require disclosure of clients and fees.

A crucial aspect of the plan is to ensure the definition of "lobbyist" includes standalone commercial firms, in-house experts, as well as trades unions and charities.

Around 90% of the 514 responses to Findlay's recent consultation supported the plans.

But the nature of the proposals angered the SCVO, whose members would be covered by the legislation, and it referred to the moves as "undemocratic and immoral".

In its consultation response, the SCVO argued that the bill promises "the biggest setback in equal opportunities the Scottish Parliament has seen", adding: "The register will almost definitely lead to a two-tier culture in political communication; with those registered being granted access at will and those who are not registered being viewed with suspicion."

The SCVO also raised the suggestion that registration may have a cost implication, adding: "If lobbyists were to be charged for this it would lead to access for those who have resources and no access for those who have not."

But the SCVO, which receives a £1.2 million core grant from the Scottish Government, has itself been trying to sell advice on how to lobby politicians.

On Wednesday, the SCVO was due to host an "engaging with the Scottish Parliament" event that flagged up its expertise in lobbying.

The blurb noted: "How can we influence policy development? Which routes are the most effective for voluntary organisations? How can we get our message across effectively? What are the pros and cons of different lobbying tools, and the pitfalls to avoid?"

Participants were told that upon "completion of the course", they would "be aware of tools for lobbying the Scottish Parliament".

Fees for the session ranged from £100 for SCVO members, £180 for other third-sector groups, and £230 for organisations in the public and private sectors. The event was cancelled due to lack of interest.

The SCVO's response to the Findlay consultation has also been questioned. Although the body has more than 1000 members, only 13 endorsed the SCVO's response before it was lodged.

Nil By Mouth, a leading anti-sectarianism charity and SCVO member, supports the planned legislation.

Its consultation response stated: "Nil By Mouth is relaxed about the proposals contained within this consultation and would be happy to comply with any register established upon the principles contained within this document."

Findlay said: "I am astonished that the most strident [opposition to] increasing the transparency of lobbying activity comes from SCVO.

"They claim their response to my consultation is representative of their members, yet only 13 of their 1400 members were willing to sign up to their submission. They also make the extraordinary claim that 'this Bill proposes the biggest setback in equal opportunities the Scottish Parliament has seen'. If SCVO want to be taken seriously on this issue they need to stop this nonsense."

A spokesman for Spinwatch, a group that monitors the public affairs industry, said: "Obviously small citizens' groups would be exempted from the requirement to register. But SCVO also represents large charities which increasingly lobby for contracts to run public services – surely a matter for legitimate public interest."

John Downie, SCVO's director of public affairs, said his body's consultation response had been endorsed by 13 members and its policy committee: "One of SCVO's strategic priorities is to support third sector organisations to achieve their missions. We therefore run an extensive programme of training and events - SCVO members receive substantial discounts on any paid for courses. Part of our role is to help the sector engage with the Parliament and Government, which is why this course is offered."