Southampton Tories have been accused of undermining the council’s hardline truancy policy by offering families free term-time only entry to the city’s new £15m Titanic museum.

Labour attacked the giveaway, which began this week, while grilling ruling Conservatives on Southampton’s high levels of school truancy.

Although they are improving, the city has some of the worst attendance rates of any local authority in England with absence having a major impact on exam results.

Nearly 100,000 households in Southampton have been invited to visit the city’s new SeaCity Museum this year for free.

But the offer of entry for a family of two adults and three children, or three adults, excludes school holidays.

The timing of the giveaway, weeks before crunch local elections, has already been criticised by Labour leaders who added it should not have been a “priority” amid service cuts and job losses.

Labour Councillor Don Thomas said: “It seems quite crazy that at this time with poor attendances and all the agencies working so hard to discourage hooky in Southampton schools that this Tory council seems, by offering free vouchers during school time, to be supporting parents removing children from school.

“It surely would not have taken a genius to work out that the council could discourage families from taking days off from school by simply putting on the voucher ‘children not free during school hours’.”

The city’s education boss councillor Jeremy Moulton said: “Labour have made it clear they oppose the new SeaCity Museum, despite it being a huge success.

“They also opposed the free tickets to local residents. Obviously people can take their children to the museum after school or at weekends, so the suggestion that limiting free tickets to term time encourages truancy is really just a silly partisan comment about what is a very serious topic.”

Southampton was ranked 140th out of 152 for the proportion of lessons missed in secondary schools in 2010/11.

Absence figures have improved thanks to work in schools, supported by the council, but 7.6 per cent of all lessons are missed at the city’s secondary schools, and 5.4 per cent of primary school sessions.

The council has forecast SeaCity will attract more than 150,000 visitors a year.

Civic leaders say they will not be making a great loss on the free ticket giveaway as they only expected around 12,000 city residents to have paid to visit – worth £70,000 to £80,000 in income.