As the dust settled on Alan Shatter's resignation last night, the immediate speculation centred on the Fine Gael young turks, Simon Coveney and Leo Varadkar, as replacements for the Dublin South TD in the Department of Justice.

However, wiser political heads were tipping Frances Fitzgerald, the Minister for Children, to take over the department.

They pointed to a number of factors which would favour Ms Fitzgerald.

Firstly, she is a staunch ally of Enda Kenny, having backed him in the Fine Gael heave.

The Taoiseach's inner Cabinet core comprised Alan Shatter, Phil Hogan, James Reilly, Chief Whip Paul Kehoe and Fitzgerald - those who stood with him in June 2010.

Shatter is now gone, and Hogan is tipped to become Ireland’s next European Commissioner, while Reilly has his own troubles.

Given the sensitive nature of the issues facing the department, perhaps Kenny felt he could not trust Varadkar not to cause trouble in the Stephen’s Green.

Coveney is keeping the farmers happy in Agriculture, and Fine Gael will not want to lose their support as other voters wobble on the party.

It is being speculated that Kenny and his department will now take a much more hands on approach in the Department of Justice, similar to their approach to the Department of Health but perhaps not quite as severe.

Fitzgerald, as a Kenny ally, can be relied upon and trusted not to deviate much from the Taoiseach’s approach.

In the midst of the recent justice controversies, a Cabinet sub-committee on justice reform was also established to see through new proposals such as the establishment of the independent Garda oversight authority.

Mr Kenny sits on that committee, as does the Minister for Justice, Tánaiste Eamon Gilmore, Minister for Communications Pat Rabbitte and Attorney General Máire Whelan.

Given the new structures in place, Fitzgerald may not command or enjoy the autonomy Shatter had during his tenure.

She is also a Fine Gael liberal, closer to Labour on many issues than some others in the senior party.

One of her tasks will be to oversee the gay marriage referendum; Labour can live with Fitzgerald in charge of that one.

Fine Gael parliamentary party chairman Charlie Flanagan will be a popular choice as new Minister for Children, having served as children's spokesman in Opposition.

The Laois-Offaly TD voted against Kenny in the heave, but that hasn’t stood in his way, and he has proved an effective and hard-working party chair.