Earlier this month, the conductor Sir Simon Rattle, formerly with the City of Birmingham Symphony Orchestra and recently appointed conductor of the Berlin Philharmonic, described the venue in extremely blunt terms, including the "worst concert arena" remark.
"It was a diabolical change going there from Birmingham," he said. "The will to live slips away in the first half-hour of rehearsal."
Sir Simon has influence with the Prime Minister and Crhis Smith, the Secretary of State for Culture, and the Government is keen to avoid accusations that London's one lasting symbol of the 1951 Festival of Britain has been ignored during millennium celebrations.
The Festival Hall, which remains popular among concert-goers despite its location among the little-loved concrete walkways on the South Bank, will be given a make-over in time for its 50th birthday in 2001.
Today Karsten Witt, chief executive of the South Bank Centre, will give details of a pounds 10m-plus redevelopment, to be financed by the Heritage Lottery Fund.
It is understood the bulk of the improvements will be concentrated on the public areas. Foyers will be improved and, most importantly, terraces will be opened up on the river frontage, allowing concert-goers to stroll and drink while overlooking the Thames. One insider said yesterday: "The idea is to go back to the original 1951 version, to recreate not just the look but the atmosphere of the original, and once again to open up the hall to the river."
A masterplan to redevelop the rest of the complex, involving possible demolition of its concrete walkways, and the Hayward Gallery and Purcell Room (the smallest concert hall) is still being studied. But the improvements to the Festival Hall will go ahead.
The architectural company Allies and Morrison has already done preliminary work on the Festival Hall and will be among the favourites to secure the contract for the redevelopment. The American-born architect Rick Mather has overall responsibility for the masterplan covering the South Bank area.
That involves expanded film facilities on the site: the British Film Institute intends to sell its West End headquarters and move to the South Bank. The sale will raise enough to build a new headquarters and a National Film & Television School, and enlarge the National Film Theatre and the Museum of the Moving Image.
The plan also includes demolishing the still-controversial Sixties buildings at the heart of the centre - the Queen Elizabeth Hall, the Purcell Room and the Hayward Gallery.
But Mr Mather has indicated he has been having second thoughts about the demolition. He said recently: "You wouldn't call these buildings beautiful and since they were built I've been standing there thinking how I'd improve them.
"But they're the most potent period piece of the Sixties. The pendulum of taste is swinging back to the Sixties, just ask anyone under 30."
Mr Mather's most startling idea is to create a "hill" on Jubilee Gardens, which lie between the South Bank Centre and County Hall. The hill would slope towards the Thames, with shops and other accommodation built underneath it.
There is no comfort in the announcement for Sir Simon Rattle and others concerned about the acoustics.
But a separate committee will report later this year on what changes need to be made.