The National Union of Journalists is accusing PA News of "shark-like and ruthless behaviour" after it encouraged editors to take up its own lobby service.

The union claims this amounts to encouraging editors to sack their own parliamentary staff and use PA instead, in a move which it says would "undermine regional journalism".

PA sent an e-mail to a number of regional editors offering what it hails as a "tailored service from Westminster… for a fraction of the cost".

NUJ president Chris Morley said: "PA's sly suggestion to regional newspaper executives to sack their Westminster correspondents is outrageous.

"It is an attack on the diversity of journalism within our major cities outside London."

"Regional newspaper circulations are being hammered in no small measure as a result of massive editorial cost-cutting in recent years which has served to drive out local content from our newspapers.

"This shark-like and ruthless behaviour is totally unacceptable and will serve only to make the Press Association a pariah to journalists as an employer."

But Gavin Bargate, PA’s managing editor, said: "For several years PA has run a very successful service, recently rebranded as Lobby Extra, which provides tailored news stories from Westminster to regional newspapers and other publications. Two more major newspapers recently opted to take the service."

"In response to requests from the industry it is normal practice for PA from time to time to alert our customers to the specialist services we offer which may be of benefit to them.

"There is clearly no obligation to take these services and editors will make the final decisions in the best interests of their newspapers."

NUJ general secretary Jeremy Dear added: "PA is of course entitled to offer its portfolio of services to a range of clients, but to make a direct approach to regional editors pushing a service which directly threatens the jobs of fellow journalists is utterly disgraceful."