The Scottish Premier League have confirmed that Hearts must stave off administration until May 20 if they are to avoid being hit with a points deduction – and almost certain relegation – this season.

The Tynecastle club's future was shrouded in uncertainty last night after a Lithuanian court reportedly began bankruptcy proceedings against Ukio Bankas, the bank to which Hearts owe £15m.

It is thought the possible consequences of that move include the administrators of the bank calling in the debt and tipping Hearts into administration.

Reports had suggested that Hearts would have to steer clear of such a scenario until June 1 to avoid being hit with a points penalty for this season, a move which would almost certainly consign Gary Locke's team to the first division.

Under SPL rules, a sanction is applied of the greater of 10 points or a third of last season's total, rounded up – in Hearts' case 18 points as a result of their 52 points recorded last May – which currently would put the Tynecastle side seven points behind bottom club Dundee on 22 points with just three matches remaining. However, the SPL yesterday revealed that Hearts must reach the 'close-season', which is defined as the day following the last league match of the campaign on May 19, without being going into administration to avoid a points deduction this term.

Thereafter, assuming they are able to continue playing, any insolvency event would result in the team beginning next season with the points deduction, again a third of the previous season's total. As things stand, that would mean starting next term on minus 14 points.

Tynecastle will have a full house tomorrow for what, from Hearts' point of view, is a dead rubber against St Mirren. More than 14,000 cut-price tickets have been sold for a game in which the visitors could secure their SPL safety with a victory.

The Hearts supporters have won praise for the way they have dealt with the club's financial concerns this season, raising over £1m in a share issue, and Gary Locke, the manager, has confessed that many at Tynecastle have become immune to speculation over the future of the club. "There's no point in let it worrying you until it happens. I've been here 3½ years and have heard so many rumours about this football club it's unbelievable. But we're still here and trying to win football games and hopefully that will be the case for many more years to come."

Hearts are to play Dunfermline, themselves in administration and facing an uncertain future, in a pre-season friendly at East End Park on July 13. The Edinburgh club are also expected to confirm their participation in Crusaders' three-day tournament in Ballymena Showgrounds in the next few days. Liverpool will be joined by one other high-profile side for the competition, which runs from July 25.