Elton John has criticised Watford's board of directors for trying to sell the club and fears they may be heading for a "catastrophe".
The singer, who originally became chairman and director of Watford in 1976, is "dismayed" that the club has not re-invested money earned from parachute payments from the Premier League and the sale of key players.
Ashley Young and Marlon King left the club for a combined fee of £12million, but manager Adrian Boothroyd has not been able to spend the cash.
"The chairman and leading shareholders have made it clear that they wish to sell the club, and this comes despite a profit of nearly £8million having been made last year," John said in a statement.
"Voices other than my own have already asked the question of what has happened to the money from the sale of some of our best players and the parachute payments.
"Whatever investment the directors still have in the club is likely to be devalued if stability is not brought back.
"We know from other clubs that, when stability and confidence go, then there is a danger of plummeting freefall. I fear we could be facing that catastrophe."
John sold the club to Mark Petchey in 1987, but bought back the Hornets a decade later and became president again.
He stepped down in 2002 – when the club required a full-time president – but he continues to hold a significant financial interest at Vicarage Road.
Despite Boothroyd's men hovering above the relegation zone, John has blamed the boardroom for failing to re-invest funds in the playing staff.
He continued: "I should make it clear that the manager and the players have my full support.
"However, it is clear that the playing staff has been left threadbare after the sale of leading players over the last year or so, and, even now, I understand that there are still plans for further player sales in January.
"More than anything else, confidence must be brought back to the playing staff and a real sense that there is a future at the club. If the directors do not have that optimism, then they should go."
Manager Boothroyd is aiming to bolster his injury-ravaged side after a narrow 3-2 defeat to Burnley on last night.
However, the Hornets chief looks unlikely to make any more loan signings after bringing in Darren Ward and goalkeeper Mark Tyler on Tuesday.
"Changes must be made so i'll be going around the streets of Watford to find some players," he said.
Asked whether he would be bringing anyone else in this week, he added: "What, members of the public? I doubt it. There will be changes possibly; there will be changes within the team."