The former federal speaker Peter Slipper has been ordered to attend court and face allegations he misused taxi vouchers.

In a statement, the Australian Federal Police says it has issued Mr Slipper with a summons that is linked to three offences of dishonestly causing a risk of a loss to the Commonwealth.

Mr Slipper would be charged upon appearing in court.

It comes less than a month after a Federal Court judge dismissed a sexual harassment case against him brought by former staffer James Ashby.

As part of his original claim, Mr Ashby also accused Mr Slipper of misusing taxi vouchers.

The AFP has been investigating those allegations and referred them to the Director of Public Prosecutions.

The maximum penalty for the charges on which he has been summonsed is five years' jail.

Under the Constitution, MPs cannot remain in Parliament if they have been convicted of a crime punishable by at least one year in jail.

Mr Slipper is to appear in the Canberra Magistrates Court next month.

He has repeatedly denied any wrongdoing.

A spokesman for Attorney-General Nicola Roxon has issued a statement saying Mr Slipper is entitled to a fair trial and any comments that might prejudice the case should be avoided.

Shadow attorney-general George Brandis agrees but says the Prime Minister should not have made him speaker and should have made him stand aside when the seriousness of the allegations against him became apparent.