From left to right: how the parties compare

If history is any guide Ireland's voters will opt for change - they usually do. No sitting government since 1969 has succeeded in being re-elected in the same form.

Casting a single transferable vote in 41 multi-seat constituencies, the 2.7 million electorate on 6 June will choose between the outgoing centre- left "rainbow" coalition, formed in 1994 of Fine Gael-Labour-Democratic Left, and the Fianna Fail-Progressive Democrats centre-right alternative.

Fianna Fail and Fine Gael derive from the 1922-23 civil war schism which followed British withdrawal. Fianna Fail, created in 1926 by supporters of Eamon de Valera, opposed partition and, until the Republic was declared in 1948, an oath of allegiance to the Crown under the treaty with Britain.

With its legendary electoral machine, Fianna Fail held power for 49 of the 74 years since the state was formed. More national movement than political party, it linked small farmers and urban workers under a republican umbrella. Since the Sixties, as it moved towards big business, its urban strength has been eroded by the left.

Fine Gael emerged from Michael Collins's allies who backed the treaty. Its support, notably from conservative Catholic farmers and professional classes, peaked at 39 per cent in 1979.

Fianna Fail and Fine Gael have similar economic policies. Today it is the smaller parties that give coalitions their colouring. Dick Spring's moderate Labour, founded in 1912, is the third party in size and reached its peak vote in 1992 winning 19 per cent of the vote and 33 Dail seats.

The mainly urban, middle-class Progressive Democrats, who married new- right economics and liberal social views, were launched in 1985 after a Fianna Fail split, entering government with that party from 1989-92.

The Democratic Left grew out of a splinter group from the official Republican movement which turned to constitutional politics.