Louise Casey, director of the government-created Rough Sleepers Unit, said that Shaks Ghosh, the head of Crisis, was seeking publicity to attract funds by saying that homeless people would die from the cold.
'Crisis knows that everyone is fighting for donations at this time of year to gain publicity and money by making malicious statements they know to be untrue,' she told the newspaper.
The attack was made in response to comments made by Ms Ghosh on BBC Radio 4's Today programme, when she said that hundreds of homeless were unable to find a bed for the night after the Christmas shelter had closed.
Ms Casey said Crisis had already been told that all of those who stayed at its shelter over Christmas would be allocated a bed.
She added: 'Crisis, a charity with a huge publicity machine, is seeking to undermine all of the very good work done by a lot of other smaller, and less well-funded, charities that upset that an organisation comes in for eight days a year and comes on this programme to say there are people dying on the streets,' she said.
Other charitable organisations such as Thames Reach and the Salvation Army were making a difference all year round.