Funding for Gaelic broadcasting could be reduced after ministers questioned whether or not the service offered taxpayers value for money.

The Conservative government has launched a review of the size and ambition of the BBC as part of the renewal of the corporation's royal charter.

Also considered will be the current funding model - the £145.50 licence fee - BBC impartiality and whether too many of its programmes are too populist.

Launching a Green Paper on the BBC's future, Culture Secretary John Whittingdale, said he wanted the corporation to "thrive".

But the BBC hit back saying that the review suggested "a much diminished, less popular, BBC."

Critics have claimed that programmes like The Voice, Sherlock and the Great British Bake Off, as well as channels such as Radio 1, are symptoms of dumbing down.

But the BBC insists that it is right to make the "good popular and the popular good".

The Green Paper said that supporting native languages within the British Isles was a "particularly important" issue.

With such a small market there was limited potential for commercial broadcasters, it added, "and therefore a key area where public funding can support undeserved audiences".

But, it said, audience reach has been falling across some language services in recent years and the services are expensive.

It added: "The cost per hour of indigenous language radio content in Scotland and Wales is considerably higher than cost per hour for English speaking content which raises concerns about value for money."

Scottish Cabinet Secretary for Culture, Fiona Hyslop, said that BBC reform had to "deliver improved coverage of the life of Scotland to the people of Scotland, an international perspective from Scotland and increases in Scottish production levels to help grow the industry".

SNP culture spokesman John Nicolson said that Green Paper asked “a lot of the right questions - amongst them how to anticipate viewers' changing needs in the light of new technology.”

Mr Whittingdale said questions also had to be asked about the size and scope of the BBC.

“We must at least question whether the BBC should try to be all things to all people, to serve everyone across every platform, or whether it should have a more precisely targeted mission," he said as he outlined the review process to MPs.

He also warned of "editorial failures" in the light of the Jimmy Savile abuse revelations.

Ministers also suggested that non-payment of the TV licence could be decriminalised, a move that would be popular among Tory backbenchers.

Shadow culture secretary Chris Bryant said the corporation should continue to make Strictly Come Dancing, Top Gear and The Voice, arguing that the BBC was "not just part of the national furniture, it's our greatest cultural institution.”

Mr Whittingdale denied wanting to shut down Strictly, but he said it was a legitimate question whether or not BBC programmes should be "distinct" from those on other channels.

Last week the BBC agreed to take over funding of licence fees for the over-75s - amid fears of further cuts to its funding.

In response, BBC director-general Tony Hall called for any future debate about the BBC to "be taken out of the political cycle".

The Conservative Government has also appointed an expert panel to carry out a review of the BBC.

Their investigation will also form part of the charter process.

Among those included is former Channel 5 boss Dawn Airey, who has previously called for the licence fee to be cut and for the broadcaster to consider charging for its website.

A BBC spokesman said: “Seven years on from its launch, BBC ALBA is watched by more than 700,000 viewers per week and continues to be an outstanding success which is appreciated by both Gaelic and non-Gaelic speakers alike.”