Opposition councillors have accused city council chiefs of a “political stunt” ahead of council elections, by offering a free ticket giveaway to Southampton’s new £15m Titanic museum for every household in the city.

Nearly 100,000 city households, and all council staff, will be sent letters in coming weeks offering groups of two adults and three children or three adults free entry, worth up to £25, to the new SeaCity museum.

It is due to open on April 10, to mark 100 years since the White Star liner set sail from Southampton on its ill-fated maiden voyage.

But Labour questioned how the cash-strapped council could afford the giveaway and complained the costs were not clearly identified in Tory budget proposals to save £14m over the next year.

Labour group leader Richard Williams said: “If it looks like a stunt, smells like a stunt, then it’s probably a stunt.”

The council said it would only lose up to £80,000 in income from the 12,000 city residents it predicted would have paid to visit.

Ian Woodland, from the Unite union, said: “Our members will be questioning the expense when we are forever being told by the council it has got no money. £80,000 could have been used to protect services, jobs and wages.