The shape of the battle for the Glasgow East by- election on July 24 will become clear today, as Labour selects its candidate and Solidarity announces if its leader, Tommy Sheridan, is to stand.

The shape of the battle for the Glasgow East by- election on July 24 will become clear today, as Labour selects its candidate and Solidarity announces if its leader, Tommy Sheridan, is to stand.

The SNP yesterday confirmed that it had selected John Mason, the 51-year-old leader of the opposition in Glasgow City Council, as its candidate. The councillor, an accountant whose Ballieston ward is in the east of the city, was chosen at a meeting of the local party last night.

Frances Curran, the former Scottish Socialist MSP, who is joint leader of the party after Mr Sheridan led a breakaway, is to be the SSP candidate in a seat where the hard left could pick up sufficient support to disrupt the bitter tussle between Labour and the SNP.

LibDems announced yesterday their candidate will be 30-year old Ian Robertson, a Bellahouston Academy maths teacher from Glasgow. He said his party's campaign would emphasise local jobs and youth crime, accusing Labour of being "out of touch" and the SNP of "empty promises".

Today, the Tory campaign for candidate Davena Rankin will be launched at one of the constituency's shopping centres.

Only five days after veteran Labour MP David Marshall sparked the by-election by resigning suddenly due to ill health, exchanges between Labour and SNP yesterday continued to increase in their ferocity.

The Commons row over fuel duty was brought into the campaign, with the SNP claiming they are the only ones who care about Glasgow East's motorists.

After Labour voted down Nationalist plans to limit increases in fuel duty, SNP MSP Bob Doris claimed: "Over half the people in the east end who travel to work use their car and have been let down by Labour as the cost of motoring is already high for them.

"Glasgow's Labour MPs voted against the means to provide those motorists with some relief from sky high fuel taxes. Yet again we have another example of the Labour Party taking the people of the east end for granted and neglecting them."

Labour seized on an opportunity to attack the SNP on the impact of spending cuts to Glasgow Science Centre, with job losses announced yesterday.

This is the first time Nationalists have been defending their record in an election. Labour also highlighted the announcement of the super-carrier contract bringing jobs to Clydeside, claiming the Royal Navy ships would not be built in Scotland if it were independent.

Ian Davidson, MP for Glasgow South-West, argued: "It's simple: no United Kingdom, no Clyde yards. The £3bn contract will protect 3000 jobs in Glasgow and provide apprenticeships for hundreds of young workers from across the city. While Labour stands up for Glasgow and invests in its future, the separatist policies of the SNP would close the yards in Glasgow forever."

Mr Marshall secured the seat with a comfortable 13,507 majority three years ago.