Jocelyn Hay: Activist who fought to maintain broadcasting standards and won the struggle to stop Radio 4 becoming all-news

Since the Second World War, when the BBC provided news and comfort for a nation in great peril, it has played a central role in British life and culture. That is why any proposals for radical change at the Corporation, or any sign that its standards might be slipping, deeply disturb its loyal admirers.

In the second half of the 20th century two determined women emerged as the principal defenders of the BBC's traditions. One was Mary Whitehouse, founder of the National Viewers' and Listeners' Association, who died in 2001. The other was Jocelyn Hay, who in 1983 established the Voice of the Listener, changing its name in 1991 to The Voice of the Listener and Viewer (VLV).

While Whitehouse's main target was explicit sex and declining moral standards, Hay was principally concerned to stem what she saw as the gradual dumbing-down of the Corporation's output, and to defend public service broadcasting in general. Whitehouse was resented by many broadcasters as an interfering busybody but Hay, by contrast, gained their respect. When she stepped down as chair of the VLV in 2008 to become its lifetime president, Sir David Attenborough lauded her campaigns and Jeremy Paxman commented: "She's an institution ... On the side of the angels."

What provoked her to launch the Voice of the Listener was the BBC's proposal in 1983 for major changes at Radio 4, long seen as representing the essence of the middle-class ethos – calm, informative and utterly respectable. The new plan was that it should concentrate exclusively on news and current affairs, with comedy, drama (including The Archers) and other strands abolished or moved to other parts of the radio network.

Hay summoned a public meeting that attracted 80 people. The response was so enthusiastic that she decided to go ahead and form her pressure group, running it from her home in Gravesend, Kent. At its peak it had a membership of over 3,000. With the threat to Radio 4 successfully headed off, she and her like-minded members turned their attention to other developments that, in their view, endangered the survival of broadcasting as they knew and loved it.

Ever on the look-out for new threats, Hay wrote numerous letters to the press and gave evidence before a succession of Government inquiries. When in 1985 the Peacock Committee recommended the privatisation of Radios 1 and 2, the strident opposition of Voice of the Listener was a factor in dissuading the Government from implementing the proposal.

The group campaigned tirelessly for the retention of the licence fee as the means of funding the BBC, and for the protection of educational, religious and children's broadcasting. It successfully fought the BBC's proposal to remove its main radio channels from the medium and long waves and restrict them to VHF.

Extending its brief to embrace commercial television, the VLV argued against the plan to award ITV franchises to the highest bidder. When the Government decided in 1995 to sell off the BBC's transmitters to a private company, the group at first opposed the move; but when that campaign failed, it ensured that the proceeds of the sale went to the BBC and not to the Treasury.

Hay was ever vigilant for seemingly minor changes in programming that she thought would have a long-term detrimental effect. In 1996 Radio 3, the classical music station, hired Paul Gambaccini, from its commercial rival Classic FM, as one of its main presenters. Many Radio 3 listeners were disconcerted by his Transatlantic accent and his less than reverential approach to the music, and VLV joined the successful campaign for his removal.

Yet the retention of Radio 4 in its traditional format was her principal concern. In 1998 she told an interviewer: "There is a general feeling that [Radio 4] has lost authority and has confused informality with lower standards. We are concerned about a general slippage in the standards of the spoken word."

She strongly opposed all proposals to weaken the regulation of broadcasting. In 2006 she wrote: "VLV views with great concern the relaxation in regulation in many areas, particularly to do with advertising, sponsorship, product placement and other ways of funding, particularly commercial channels. It's at great risk of interfering with the integrity of editorial decisions and our concern is that once you break the trust that viewers have in the broadcasters, you'll never get it back again. That trust is a very, very precious commodity."

Born in Swansea in 1927, the daughter of an accountant, she was sent to live with an aunt in Australia shortly after the outbreak of the Second World War. In 1945 she rejoined her parents, then living in Trieste, where she met and married Bill Hay, a Scottish army officer. Back in Britain, while raising their two daughters, she worked as a journalist and broadcaster and briefly as a publicity officer for the Girl Guides. But it was as an effective campaigner for her strongly-held values that she found her true métier – so much so that Gillian Reynolds, the radio critic of the Daily Telegraph, described her in 2008 as "possibly the best lobbyist in the whole UK".

MICHAEL LEAPMAN

Jocelyn Hay, journalist, broadcaster and campaigner: born Swansea 1927; MBE 1999, CBE 2005; died Gravesend 21 January 2014.