Unit head Louise Casey said on Saturday: "There is absolutely nothing in these allegations and I am deeply disappointed by them.

We believe the public and agencies dealing with the issue are being totally misled

Philip Burke Simon Community homeless charity

"I have nothing to hide or be ashamed of and there has certainly been no fiddling.

"The figures are coming down because of the hard work that has been done and perhaps it is jealousy that has brought these comments.

"It is a shame as such comments can undermine the phenomenal work that has and is being done."

Philip Burke, chairman of the Simon Community, said: "We stand by what we have claimed because it has come from workers involved in the count and from our own outreach workers dealing for those sleeping rough.

Homelessness workers claim the figures have been fixed

"We believe the public and agencies dealing with the issue are being totally misled and deceived by the rough sleepers unit.

"A number of people were told they would be arrested unless they went to shelters."

Chris Holmes, director of Shelter, said: "Shelter is very concerned if these allegations are found to be true.

"They need to be urgently investigated.

No increase

"There are official guidelines for conducting street counts and it is vital that they are carried out thoroughly and consistently as they indicate trends of street homelessness."

Ms Casey said she will speak to charities next week to further reassure them.

A spokesman for the Metropolitan Police said there had been no stepping up in arrests of homeless people.

He added: "Officers may make arrests under the Vagrancy Act if it is appropriate but there has been no increase."