New laws could be put in place to drive sweeping changes to the way English football is run, following failures by the sport's authorities to change the governance of the game.
A committee of MPs said the Premier League wielded too great an influence over the game in England and ordered reforms. But the culture, media and sport select committee said it had been "very disappointed" by the football authorities' response to its proposals for reform made in July 2011.
Its concerns cover financial management, the balance of power between the Premier League and the Football Association, and major financial risk-taking.
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... If football cannot reform itself, the Government should introduce legislation as soon as practically possible."
Sports minister Hugh Robertson 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 said 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."