The news further dents confidence in the embattled holiday operator after a string of profit warnings and a funding crunch.
Reports yesterday claimed Thomas Cook’s sales had fallen by 33 per cent in the two weeks to 13 January, citing a leisure industry monitor shared by tour operators to track bookings.
Shares in the group, which have fallen by over 90 per cent in the last year, fell a further five per cent.
Sources close to Thomas Cook confirmed that sales had fallen but said it was down to a planned cut in holidays on sale rather than a collapse of confidence in the brand.
Thomas Cook said it last reported UK bookings on 14 December, showing it went into January with an order book for summer 2012 that was well ahead of the wider market.
Charles Stanley analyst Douglas McNeill said the latest figures were a concern, but investors should not read too much into a two-week booking period.