The ongoing fan protests at Premier League champions Manchester United are likely to increase in recent months, according to fan group leaders, with boycotts of Old Trafford season tickets planned as pressure groups look to hit the Glazer family, Manchester United's owners, in the pocket.

At recent matches, Old Trafford has seen large numbers of fans decked in green and gold - the club's original colours when it was founded as Newton Heath in 1878 - rather than Manchester United's world-famous red shirts, as fans seek to make their feelings about the owners known. Despite the fact United have won three consecutive Premier League titles in the last three seasons. increasing concerns about the precarious state of the club's finances have prompted the protests.

Season ticket sales at Old Trafford fell from 65,000 to 58,000 this season, according to reports, as the economic crisis combined with ticket prices that have increased massively since the Glazer family took control.

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In 2005, when the Glazers took over Manchester United, a number of fans formed a breakaway club, FC United of Manchester, in protest. Andy Walsh, now FC United general manager, told the Daily Mail: "It is only now, after the true state was laid bare in the prospectus to raise the £500m bond, that the fans have taken the veil from their eyes.

"We've had many people apologising to us. There is a plan to step up the campaign and hitting the Glazers in the pocket as the next phase. The green and gold campaign has focused people's attention but there is an understanding it won't work on its own. A boycott will hit the Glazers because their business plan relied on them cranking up ticket prices and extracting more cash from supporters."

This weekend, the Manchester United Supporters Trust distributed 70,000 cards to fans in a recruiting drive. Speculation about various takeover bids continues.