In a report published at midnight, the Lords' Communications Committee voices concern about the consolidation of newspaper ownership in a small number of publishing companies.

Four companies - Trinity Mirror, Northcliffe, Newsquest and Johnston Press - now control 70pc of regional and local circulation, while one cpompany - News International - is responsible for 35pc of all national circulation.

According to the report, this runs the risk of "disproportionate influence" over news gathering being exercised by a small number of owners.

The committee is chaired by Lord Fowler, a former chairman of both the Birmingham Post group before it was bought by Trinity Mirror and the Yorkshire Post group before it was bought by Johnston's.

In its report, entitled The Ownership of the News, it says the impact of newspaper mergers on newsgathering should be explicitly considered as part of the public interest test governing takeover bids.

"The consolidation of ownership in the media that has taken place over the last years has added to the risk of disproportionate influence being exercised by a small number of companies and owners," it says.

"In order to ensure diversity of news provision the committee propose strengthening the public interest test for media mergers."

It says the communications watchdog Ofcom should be given the power to initiate an inquiry into whether a merger is in the public interest. Currently this is the province of the Competition Commission.

It also calls for local cross-media mergers between radio and newspaper companies to be subject to the same public interest test.

Lord Fowler said: "The newspaper industry is facing severe problems as readership levels fall, young people turn to other sources of news, and advertising moves to the internet.

"Even when newspapers run successful internet sites the value of the advertising they sell on these sites does not make up for the value lost. In television news the same trends are evident and audiences for news programmes have reduced.

"The result is that there has been consolidation of ownership and pressure on costs. Companies are having to make savings and this is having a particular impact on investment in news gathering and investigative and specialist journalism.

"Against this background it is important that every effort is made to ensure high quality news provision and a diversity of voices in the news. Media ownership controls remain in place to ensure that consolidation in the industry does not have an adverse impact on the public interest."