More than 1,000 families still unable to move back into their homes after the winter's floods will not have to pay any council tax until they do, the Government said.
Local Government Minister Brandon Lewis said a discount scheme originally planned to last three months would be extended, taking the cost from £4 million to £6 million.
Residents were forced from around 7,700 homes in England during the extreme weather and most have returned but Mr Lewis conceded that the drying out process for others would take "a little longer still".
Officials said that a review of serious floods that hit the country in 2007 found half of affected households returned to their properties within three months and 82% within six months.
The areas in the south with the most families still out of their homes are Hampshire and Isle of Wight (123) and Surrey (72).
Mr Lewis said: "Thankfully many people have been able to return to their homes, but for some the process of homes drying out is going to take a little longer still.
"I don't want to see any of those families having to worry about paying their council tax while they focus on getting their lives back in order.
"So from today the Government will extend its discount and no family will pay a single penny in council tax until they are safely back in the comfort of their own home."
He urged anyone who had not yet been offered a discount to contact their local councils - which have been told they will be reimbursed by central government for the cost.