Football chiefs have been warned the sport could be subject to new laws because of their failure to overhaul its governance.
A committee of MPs accused the Football Association, Premier League and Football League of failing to act after its 2011 report.
And it declared the Government could legislate "as soon as practicable" unless there is "clear progress" on its proposals in the next year.
The culture, media and sport select committee believes the Premier League wields too much influence over the game in England and had ordered reforms.
Its concerns cover financial management, the balance of power between the Premier League and the FA and major financial risk-taking.
In 2011, the committee proposed shaking up how the FA operates and making clubs adhere to financial rules, regulated by a licensing system.
But in a follow-up report MPs said the response of the football authorities to the proposals had been "very disappointing".
Committee chairman John Whittingdale said: "While some progress has been achieved, much greater reform in football is needed to make the game inclusive, sustainable and driven from the grass roots, where it should be.
"The proposals for reform so far simply don't address the fundamental problems: the licensing model, the way supporters are engaged at club level and the membership of the main [FA] board, which is not fully representative or able to balance interests adequately.
"In addition, the financial proposals were hugely disappointing: the financial risk-taking by clubs is a threat to the sustainability of football as a family and community-orientated game, which it should be.
"If football cannot reform itself, the Government should introduce legislation as soon as practically possible."
Recommendations by the committee include:
:: Reducing the size of the FA board, and making FA executives and non-executive directors the minority compared to the "vested interests" of members appointed by the professional and amateur game;
:: Limiting the Premier League and Football League to one FA board member each - the leagues currently have two apiece;
:: Fans being represented on the FA board;
:: Making information about club ownership publicly available;
:: Having the FA regulate a financial licensing system, and not leave it to the Premier League and Football League;
:: Bring in legislation to impose discipline if spending controls such as financial fair play are not adopted by clubs;
:: Long-term funding plans should be agreed for Supporters Direct (SD), a group that promotes the value of supporter ownership and influence.
Sports minister Hugh Robertson insisted the warning on legislation was no empty threat. He said: "If football does not deliver the reforms then we will look at bringing forward legislation."
In a joint statement, the FA, Premier League and Football League insisted the necessary reforms would be implemented.
It said: "Significant headway has already been made on many of these proposed reforms, not least on sustainability and transparency.
"The remaining reform proposals are the subject of consultation within the game and we are confident that the necessary progress will be made."
SD chief executive David Lampitt said: "The committee has clearly been spurred on by what they called the 'lack of direction and urgency' of the football authorities and has recognised that a few minor changes do not add up to meaningful reform.
"A timetable for proper change is now required, backed up by government intervention if it is not delivered upon.
"It is supporters who sustain the game economically - whether through tickets or TV subscriptions - and who have the long terms interests of the game at heart."