Liverpool supporters speak out on on the proposed takeover. Reuters

The fight to control Liverpool's future is heading for the high court next week, after the chairman, Martin Broughton, insisted he has the legal right to sell the club despite the opposition of Tom Hicks and George Gillett, the American owners.

Broughton and the club's managing director, Christian Purslow, and the commercial director, Ian Ayre, said they had agreed a sale to New England Sports Ventures, owners of the Boston Red Sox baseball team, a deal that would give Hicks and Gillett nothing for their shares nor their £144m loans back to the club.

NESV, a group of 17 investors led by the US multimillionaire John W Henry, has agreed to clear the club's £200m debt with the Royal Bank of Scotland, which Hicks and Gillett borrowed to buy Liverpool in the first place, and meet other liabilities of around £100m. The proposed deal has the backing of the Premier League.

Broughton announced that he has launched legal proceedings to confirm his three-man board majority has the right to conclude the sale, saying: "The owners have tried everything to prevent the deal from happening."

Fifteen minutes before a board meeting on Tuesday called to approve the sale, Hicks and Gillett sought to replace Purslow and Ayre with Mack Hicks, Tom's son, and his assistant Lori Kay McCutcheon. Broughton, in a series of interviews including one on Liverpool's website, said that move and the Americans' opposition to the sale were a "flagrant abuse" of undertakings they gave when refinancing for a third time with RBS in April.

Broughton said they agreed that he, as chairman, would have the sole right to appoint and remove directors, a power written into the club's constitution, and agreed with RBS not to obstruct "reasonable endeavours" to agree a sale. The court action is to seek approval from a judge for the sale.

"We will be seeking a declaratory judgment to say we acted within our rights," said Broughton, the British Airways chairman who was appointed to oversee the sales process in April. "George and Tom had recognised the only way of moving forward was selling the entire club, and that if they alone said that is what they were going to do it would not have any credibility because they no longer had any credibility. They agreed to appoint an independent chairman to add credibility to the process. I was not prepared to be their patsy, adding credibility to a process that did not have it. They gave those written undertakings and on Tuesday they flagrantly abused those undertakings."

A spokesman for Hicks said he is adamant his new Liverpool board is legal and has the authority to vote against a sale. "There were no such undertakings given to Broughton," he said, "the board has been legally reconstituted, and the new board does not approve this proposed transaction."

The deadline for repaying the loans to RBS, £237m in total, is next Friday, 15 October. The bank has provided assurances there will be no further refinancing for Hicks and Gillett, who appear liable to lose more than their £144m if RBS places Liverpool in administration, because the bank could pursue them personally for the £237m. Broughton therefore argued it is in the Americans' interests to accept a deal he is legally entitled to conclude.

"I think it's rather sad," he said of the public boardroom battle. "Their legacy by any stretch of the imagination was never going to be good. This was the one final opportunity where they could walk away with their heads held high, saying to the Liverpool fans: 'We said we would deliver you the right owners, we have, and we did it at great personal cost.' But they chose, effectively, in my view, to suffer the great personal cost and walk away humiliated as a result. That's their choice and I think it's a pity."

Both parties will receive 24 hours' notice before the case is heard and an appeal process is available to Hicks and Gillett should they lose.

Were they to be successful, however, they would still need to repay RBS its £237m by 15 October. If they fail to do so RBS will be expected to put Kop Holdings, which owns Liverpool, briefly into administration, in effect removing Hicks's and Gillett's ownership completely, then to sell it on to NESV.

The Premier League would not deduct nine points from Liverpool – its standard penalty for administration – because it will regard the club itself as still solvent.

The league said yesterday it had been "formally notified" by Liverpool of the proposed sale and intends to approve the directors and financial plans tomorrow.

NESV issued a statement last night that confirmed their bid "has been selected by the club's board of directors" and outlined its plan "to create a long-term financially solid foundation for Liverpool FC, dedicated to ensuring that the club has the resources to build for the future, including the removal of all acquisition debt".

The commitment is to repaying to RBS the £200m and to do so in cash and not with further debt to be loaded on to the club. The other £100m is to cover the club's other liabilities, including initial debt taken on to finance the new stadium, with which Hicks and Gillett could not proceed.

NESV's offer is one of only two firm proposals received for Liverpool during an exhaustive search for new owners; the other came from unnamed interests in Asia. The new US investors, in a radical departure from established club policy likely to enrage Liverpool city council and local residents' groups, is not committing to building the new stadium, on which the entire neighbourhood is relying for regeneration. NESV said it may redevelop Anfield instead.