Three major newspaper publishers have called for the regional press to be represented on the panel looking into press ethics in the wake of the phone hacking scandal.

The seven-person team of assessors headed by Lord Justice Leveson includes two distinguished former political editors but no regional or local press representatives.

An application by Associated Newspapers to add further representatives to the panel was supported by Trinity Mirror, the Newspaper Publishers’ Association and Guardian News and Media.

Associated’s counsel, Jonathan Caplan QC, said it did not wish to be “confrontational”, but there were concerns at the lack of anyone among the six assessors, appointed by ministers, who represented the tabloid, mid-market, regional press.

Mr Caplan said such an omission was “unfortunate” in an inquiry which raised fundamental issues for the future conduct, regulation and ownership of the newspaper industry.

The panel of assessors currently comprises Sir David Bell, former chairman of the Financial Times; Shami Chakribati, director of human rights watchdog Liberty; Lord (David) Currie, the former chairman of Ofcom; Elinor Goodman, the one-time political editor of Channel 4 News; George Jones, former political editor of the Daily Telegraph; and Sir Paul Scott-Lee, former chief constable of West Midlands police.

Gillian Phillips, director of editorial legal services for The Guardian, said: “Our view is that tabloid and mid-market papers, as well as regional papers, will play a vital part in the story and we believe it is important that those assisting the inquiry reflect the plurality and divergence of the wider UK media.”

Lord Justice Leveson said he would give his ruling on the application at a later date.

He also confirmed that the role of assessors was limited to assisting from within their area of expertise, with the conclusion being “mine and mine alone”.

He added: “It is of critical importance throughout this inquiry that I have the help of everybody. I have a vast and difficult task to address within a comparatively short period of time.

“I accept the importance that it holds for your clients and for the industry, the profession.

“I will only start to be able to achieve a sensible resolution of these issues if everybody is pulling in the same direction, albeit from their different standpoints.

“I am not asking people to compromise their views or beliefs but I will want to make sure that I have everyone’s point of view and, if there is any perspective which it is thought I have missed from the evidence that I propose to call or in any other way, then I would be grateful if your clients, and indeed every other core participant, ensure the team are aware of the gap.”

Prime Minister David Cameron announced the inquiry, which will start in London later this year, in July, following disclosures about phone hacking by the News of the World.

It is expected to recommend a new regulatory regime for the industry to replace the Press Complaints Commission which the Prime Minister has branded “ineffective and institutionally conflicted.”