The Association of Convenience Stores is calling on the government to allow its MPs a free vote on the tobacco display ban.

Conservative shadow health secretary Andrew Lansley announced in a debate on the Health Bill in the House of Commons this week he would allow Tory MPs the freedom to vote as they choose, rather than having to toe the party line. The Liberal Democrats also pledged to allow a free vote.

"Conservatives and Liberal Democrats are free to make up their minds - so should government backbenchers be," said ACS chief executive James Lowman. "Ministers should not railroad this."

The ACS is fighting the Government's plans to ban tobacco display, which it claims will burden convenience stores with unnecessary expense without being effective in reducing underage smoking.