Concerns have been raised over plans for new 50p coins without the Britannia figure on the tails side.

When he was chancellor, Gordon Brown was criticised by the Tories over his plans to promote British values because he approved the competition to find new designs minus Britannia.

However, nationalists said the move represented an opportunity to celebrate other aspects of British culture not always recognised.

The contest means the famous character will not be the automatic default design on the tails side of a British full circulation coin for the first time since 1672.

Previously, special edition 50p coins commemorating events such as the 150th anniversary of the Victoria Cross have appeared without Britannia.

Alex Neil, SNP MSP for Central Scotland, said: "I think we should have Rabbie Burns on the coin to celebrate the Year of Homecoming Scotland for the bard's 250th anniversary next year.

"Burns has done far more for tourism than Britannia ever did."

However, David Mundell, shadow Scottish secretary, said: "Gordon Brown is showing a complete lack of respect for tradition. Once again all he's offering is change for change's sake with no idea why he's doing it."

Shadow foreign secretary William Hague said that Britannia has been "an enduring symbol of British pride and history".

The Royal Mint launched the £30,000 competition two years ago, allowing themes "to represent Britain, such as flora or fauna, geographic features, social, political or cultural achievements or British institutions", or to interpret heraldry "in an imaginative and creative way".

More than 4000 designs were viewed by the Royal Mint's advisory committee on coin design. The redesigns are due to be unveiled in April. Each design winner is to receive £5000.

The new designers had to work within constraints and the Mint will not allow them to touch the portrait of the Queen, which will remain on the topside.

The Mint sought designs for 1p, 2p, 5p, 10p, 20p and 50p coins. The current designs for those coins were prepared for decimalisation in 1971, while the 20p coin was designed in 1982 and the £1 coin appeared in 1983.