Southampton City Council has confirmed its intention to sell key works of art from the collection of Southampton City Art Gallery.

The council believes that the sale of a sculpture by August Rodin and a painting by Alfred Munnings will help pay for a new £15 museum about the Titanic due to open in 2012.

The two Rodins, Eve and Crouching Woman, and After the Race by Munnings, are valued together at £5m. The entire collection, which includes works by Turner, Lowry, Picasso and Monet, is valued at £180m.

Southampton’s culture boss, John Hannides, chairman of the city’s culture committee, said: “The Munnings has not been seen in Southampton for quite some time and that also goes for the other items too. While they have been on display on occasions they are not central to the collection”. The Rodins have been kept in store.

“We have looked at all potential options for funding, and we have not yet taken a decision to sell them, but without this it would be very difficult to see how we might otherwise be able to fund the heritage museum” he said.

But Guardian art critic Jonathan Jones wrote this week that the collection has a long standing reputation with works of art from the Renaissance. “But it also has a policy of buying modern art, including paintings by Bridget Riley and Chris Ofili. It displays its collection of about 3,500 works in rotation, and uses it to create imaginative exhibitions that mingle past and present.

“It seems to be the collection’s very liveliness that has opened it to attack. First the Riley acquisition was pilloried in the city newspaper; now the council has decided the collection is fair game.”

The Visual Arts and Galleries Association said the sale would be seen as “a test case for cash-strapped councils using one part of their collections to support another. This could have a fundamental effect on museum collections across the country”.