Tony Hall will launch a staunch defence of the BBC licence fee this week, suggesting there is an anxiety to privatise the corporation.

The BBC director general will use a speech in Oxford to hit back at critics including Lord Grade, a former chairman of the corporation, who have called for the licence fee to be shared with other public-service broadcasters and producers – a concept dubbed "top slicing" or "contestable funding".

Hall will argue that sharing it with other organisations would weaken not only the corporation but UK broadcasting generally.

His latest intervention heralds an intensifying of the debate about the BBC's future, as the corporation steps up its lobbying efforts ahead of negotiations with the government for a new 10 year royal charter and funding deal. The BBC's existing charter and licence-fee agreements run to the end of 2016.

He will also be aiming to move the debate on from a string of crises, pre-dating his appointment as director general in April last year but which have dogged the BBC, including the continuing fallout from the Jimmy Savile scandal and rows over executive redundancy payoffs and the £100m Digital Media Initiative IT debacle."Top-slicing means just that – less and less funding for content and services that we know people love," Hall will tell the Oxford Media Convention on Wednesday. "And by weakening the BBC, you also weaken the competitive intensity that underpins the success of UK broadcasting.

"Contestable funding feels like a solution in search of a problem. In the anxiety to privatise the BBC, this proposal suggests nationalising the rest of the sector.

"But, most importantly, the fragmentation of the licence fee risks de-stabilising a broadcasting model that works. A model that is based on competition for quality – but not funding – between public and private broadcasters." In an earlier speech defending the BBC funding model in November, Hall said the BBC must be more aggressive and "less British" about using its own TV, radio and online services to make the case for the licence fee.

There is exasperation among BBC executives with former senior corporation figures – and at least one, David Dimbleby, whom they still employ – who have argued variously for its scope to be curtailed and funding to be shared with others. Dimbleby, the veteran BBC presenter, has said it should pull back a bit from some of the things it does and merge BBC2 and BBC4.

His comments came shortly after Roger Mosey, a former senior BBC executive who oversaw its successful London 2012 Olympics coverage, suggested that sharing the licence fee with other broadcasters might help promote pluralism and diversity.

Earlier this month, Grade told a Commons culture select committee hearing that the BBCwas too big and had become unmanageable, suggesting swaths of the organisation should be outsourced to the private sector. He also backed merging BBC2 and BBC4 and said the licence fee should be shared with Channel 4. Hall will address the arguments made by Grade and others directly in his speech, the tone of which is likely to raise the temperature in the debate about the BBC's future considerably.

He will say of the BBC's critics: "Instead of saying that the licence fee is so bad that no one should have it, they have begun to suggest that the licence fee is so good that everyone should have it. They say the licence fee should be competed for and allocated to a range of providers.

"What purpose would this serve? Would it make the BBC more responsive and accountable? We are not a monopoly supplier of public-service broadcasting. We are subject to intense competition in a market where consumers can easily switch between providers. Would contestable funding mean more choice for audiences? Audiences have never had a greater, richer amount of media choice."