The PRCA will consult members on proposals to open the register to non-members, free of charge.
The news follows plans made by UKPAC last month to open up its own register to non-members of the CIPR and APPC, and will be seen as a challenge to UKPAC's hopes of being first in line to achieve statutory status.
One senior agency source suggested the PRCA was aiming to show its service is 'fit for purpose - a demonstration of how a statutory register might look'.
PRCA chief executive Francis Ingham admitted that there were arguments 'both in favour of and against' the proposals, adding that he came to it with an 'open mind'.
He added: 'We appear to have reached a stalemate on progressing the statutory register. UKPAC continues to have no credibility and the Government's plans appear to be going slowly. So, if we want a register, why not just do it?'
Ingham denied that the plans were an attempt to displace UKPAC in its hope of feeding its service into the Government's statutory plans.
However, he did state that a broadened register would make a distinction between those who were regulated via the PRCA Public Affairs Code of Conduct and those who were not, 'echoing proposals made to Cabinet Office Minister Mark Harper'.
Ingham claimed the PRCA register had several benefits over UKPAC's: 'I think it's broader, it's bigger, it's been going for 15 years, and does not have mistakes in it.'
However, UKPAC chairman Elizabeth France responded by stating there were no longer mistakes in her list of lobbyists, other than any that had been made by those registering.
France also questioned Ingham's claim that his new service would be free of charge, while UKPAC planned to charge for its open register.
'There would have to be an administration cost,' she said. 'We don't know why members should pay for that. We think it's unrealistic.'
France added she was still considering how much to charge, but aimed to have a small number of non-members on UKPAC's register by September.