Fifteen million a people a year who travel by air or sea between Britain and the Irish Republic will face formal passport checks for the first time in more than 80 years, under immigration legislation published today .

But no compulsory passport checks are to be imposed on the 224-mile land border between the republic and Northern Ireland, although ad hoc "intelligence-led" immigration checks will be carried out by mobile teams of Border Agency staff.

Ministers say the proposal in the citizenship and immigration bill will "plug a critical gap" in Britain's border security as they introduce the multibillion pound "electronic border" over the next five years. The programme will enable travellers to be checked against watch lists before they get on the plane or ferry.

The legislation will bring to an end the common travel area between the republic and Britain, which dates back to the creation of the Irish Free State in 1922. Apart from limited attempts to control the land border during and after the second world war the common travel area has been a free movement zone for more than 80 years.

A Home Office impact assessment published alongside the bill acknowledged the possibility of large queues building up as a result of the introduction of the passport checks, particularly at Welsh ferry ports for those coming from Ireland. Officials hope to minimise such delays.

At the same time as the legislation was published in London yesterday, the Irish government announced that it will introduce its own new border control system from next year. The Irish justice minister, Dermot Ahern, said the Irish border information system would also screen for illegal migrants by checking travel data collected by airlines and ferry companies before departure and checking it against watch lists.

A British proposal to introduce passport checks for those who fly from Belfast to the rest of the UK was dropped after strong opposition from Conservatives and Ulster Unionists. The imposition of border controls will however also apply to those who travel between Britain and the Isle of Man, Jersey and Guernsey.

The citizenship and immigration bill introduces radical reforms to British citizenship, including the introduction of a requirement for migrants to speak English and obey the law if they want to get a British passport.