FEARS of an explosion in Hampshire's rat population have been sparked today by a county MP.

Chris Huhne has launched an investigation after dozens of constituents told him they had spotted the disease-carrying vermin.

Now he is demanding to know why they are on the increase.

Possible theories include global warming, a drop-off in pest control by water companies and fortnightly council bin collections.

The MP said: "Experts seem to think it has something to do with what has happened in the wake of water privatisation.

"In the old days, water utilities carried out regular sewer baiting to keep down the rat population with poison."

But a Southern Water spokesman said: "Local authorities are responsible for test baiting to show the existence of rats. If they find evidence of rats in our sewers, we arrange eradication."