Birmingham City Council's first all-out elections for more than a decade will be held in 2018, a year later than initially planned.
Local Government Secretary Eric Pickles will place a bill before Parliament on Monday moving the date from 2017 as initially decided in December.
The decision to move to all-out elections, where the whole council is elected in one go rather than thirds as they currently are, was taken after government troubleshooter Sir Bob Kerslake called for sweeping changes to the way the city council was run and elected in his review last year.
Although there has been no official statement on the reason for putting the election back, it is thought the reorganisation of the local authority is more complex than initially thought and more breathing space is needed.
In a message to colleagues, council leader Sir Albert Bore said: "I suspect this will not impact on the work of the Boundary Commission but simply gives a lengthier period in which to put arrangements in place for whatever comes out of the Boundary Commission in 2016."
It will give councillors, who win the elections this May and in May 2016, an extra year in the post before facing re-election.
The Local Government Boundary Commission, whose chairman Max Caller met councillors earlier this week, is currently looking at how many councillors the local authority needs to be effective before carrying out a review of wards and boundaries later in the year.
Meanwhile, also prompted by Kerslake, the council is reviewing its constitution, which among other things is likely to see the number of scrutiny committees cut from nine to five, so is not yet in a position to provide a figure.
Kerslake recommended cutting the number of councillors down to 100, representing equally sized, single-member wards.
But the Boundary Commission appears more willing to consider varied ward sizes which follow community lines and with one, two or three councillors depending on the number of voters.
The motion on the City of Birmingham (Scheme of Elections) Order 2015 is listed on Monday's Parliamentary business.
The last time there were all out elections in Birmingham was in 2004.