The DTI, the Stock Exchange and a number of practitioners are to press for progress on a voluntary code of conduct for the industry, after initiatives begun last year have stalled.
Official sources say news on a series of insider dealing investigations will also serve as a warning for consultants to stamp out leaks to City analysts, journalists and market insiders.
"Our role is to ensure that no-one benefits from price sensitive information and to ensure that practices that lead to such a culture are discouraged," one senior regulatory source said.
The DTI is currently investigating several leaks in pursuit of possible insider dealing charges, including a profits warning from building group Caradon, US oil firm Arco's hostile bid for Aran and dealings in Midlands builders' merchant Blagg, all in 1995.
It is also conducting a series of further insider dealing inquiries, including one into a City ring that is understood to have made millions from dealing illicitly in shares in BTR, Williams Holdings and Rothmans.
The identities of several of the brokers and individuals in that inquiry are known to the Independent on Sunday but cannot be published for legal reasons. At least one journalist on a rival Sunday newspaper is also understood to have been interviewed by the DTI.
Investigations by the Stock Exchange and the DTI last year into share trades before Caradon's profit warning in September 1995 prompted a scramble by parts of PR industry to clean up its act.
The inquiry centres on dealings by merchant bank Robert Fleming, following information allegedly passed on to it by top City PR firm Financial Dynamics. Two Flemings analysts and an equity salesman left the bank after the affair.
Financial Dynamics staff, including chairman Tony Knox, are also understood to have been interviewed over the Arco bid for Aran. Mr Knox, who was on holiday last week, has denied any wrongdoing.
Both inquiries have yet to be completed, but the DTI is concerned that moves towards a code of conduct have fallen on stony ground after the publicity died down.
Alone among the big players in the City, PR consultants remain unregulated despite calls from influential quarters, including the Takeover Panel and the Institute of Public Relations.
This weekend, the IPR's new president Simon Lewis - who is the director of public affairs at TransCo, the transmission arm of British Gas - repeated calls for regulators and City institutions to take the lead in putting financial PR on regulated footing.
The IPR plans to meet shortly with the Association of British Insurers to press its case.
One of the DTI's problems in clamping down is that the law, as interpreted so far, means that PR consultants who gain no benefit from leaks may not have committed any offence.