The Taoiseach Brian Cowen has now demanded an explanation from another Fianna Fáil Senator over his expenses.

Senator Larry Butler was claiming travel allowances from County Carlow, despite having a home and political base in Dublin.

It comes as pressure mounts on Senator Ivor Callely to resign from the Fianna Fáil party or have the whip removed, while he is under Parliamentary inquiry over his expenses.

Larry Butler was a Councillor in Dun Laoghaire from 1991 to 2007 when he was elected to the Seanad.

The Senator still owns a house in Foxrock on Dublin's Southside and the Fianna Fáíl party insists he is a representative for Dun Laoghaire.

But he is insisting he moved to County Carlow in 2007 because he is originally from there.

This has allowed him claim €20,000 a year more in travel expenses.

Fianna Fáil has confirmed the Taoiseach is demanding an explanation from Senator Butler over his expenses.

Meanwhile even though Senator Callelly insisting he has done nothing wrong his party is not willing to stand by him during the parliamentary probe of his expenses.

Last night a statement declared attempts to remove him from Fianna Fáil will be made by the Chief Whip at the next PP meeting unless he decided to remove himself first.