The NS, which is campaigning for curbs on the taxpayer-funded publications, has highlighted instances where they have favourably compared their services to independent local papers.

For instance, Hackney Borough Council's publication Hackney Today says its offers the "largest reach in the borough of any local paper" and takes "all sorts of advertisements including statutory notices and recruitment at extremely competitive rates."

And H&F News, published by the London Borough of Hammersmith and Fulham, says it has "more than double the readers of our nearest competitor" and quotes readership statistics from a survey undertaken by a commercial research company.

The NS audit of 436 local authorities across the UK found that many councils are publishing their own newspapers and many have names similar to those of independent local newspapers or are laid out to appear the same.

It found half of the local authorities surveyed in London published a newspaper or magazine on a monthly or more frequent basis and 90pc contained or accepted third–party or public sector advertising.

Outside of London, 54pc of local authority publications contain news which relates to topics other than council services, and nearly a third contain advertising.

In a submission to ministers last month, the NS argued that council services which compete directly with local media for audience and advertising should be prohibited and called for market impact tests to be conducted before local authorities are allowed to launch new publications.

Commenting on the survey this week, media commentator Roy Greenslade said council newspapers were "undermining the only publications that hold local power to account."

"They are anti-democratic in both spirit and in practice, and their disappearance will not matter one whit to the public. It is time to put all such publications to the sword before they kill off independent local papers," he said.