The government’s new ‘lobbying tsar’ has warned law firms that they risk criminal proceedings if they are found to have approached ministers without signing up to a new mandatory register.

So far only one traditional law firm – magic circle outfit Clifford Chance – has joined the register of consultant lobbyists since it opened in March under the Transparency of Lobbying, Non-Party Campaigning and Trade Union Administration Act 2014. PwC Legal is also registered.

The act requires anyone who lobbies on behalf of a third party to register.

The Gazette understands talks will be held next month between official registrar Alison White and the Solicitors Regulation Authority about the requirements of the legislation.

In an exclusive interview, White revealed some City firms have told her they do not intend to sign up to the register, despite running prominent public affairs teams.

While White stressed she has no reason to believe any firm is acting in breach of the law, she warned that if any firms were to do so they could face civil or even criminal penalties.

‘I take a much more relaxed view about organisations who want to work with me and understand what it is they need to do, rather than actively set out to get out of their statutory obligations,’ she said.

‘It is perfectly possible that organisations in the course of their interaction with ministers may potentially be caught up by the legislation. The critical issue is you cannot have that kind of interaction until you are registered in advance.’

White said that the traditional lobbying industry is ‘particularly anxious’ about law and accountancy firms not being compelled to register.

She said communications might take place ‘once in a blue moon’ but if firms cannot be sure these will not happen, they should stay on the register indefinitely.

‘You need to be really careful that in an enthusiastic moment a partner has a conversation with a minister which constitutes direct communication as far as the act is concerned – you may not think it is lobbying,’ White (pictured) said.

Simon Gleeson, partner and co-chair of the public policy group at Clifford Chance, said its work involved ‘communicating with UK government policymakers’ on complex matters, ‘so we took the early decision to become the first registered law firm to ensure that we could fully represent the interests of our clients.’

But other firms remain sceptical about the need to register at this stage. A spokesman for Bircham Dyson Bell said: ‘BDB has a dedicated public affairs practice and will register if any work falls within the act’s definition of consultant lobbying. At present, none of the work we are doing for clients falls within that definition.’

It has been suggested that firms may be prevented from registering by the requirements of client confidentiality. However, an SRA spokesman said because the Code of Conduct states that solicitors must uphold the rule of law, a mandatory register would supersede the need to retain client confidentiality.