A group of prison guards help a rally outside Prime Minister Stephen Harper’s constituency office in Calgary, Saturday.

The guards say federal spending cuts and the government’s move to employ mandatory custody for certain crimes are causing overcrowding at the country’s 52 federal prisons.

This is making the guards’ jobs more difficult and hazardous, according to the protesters.

They pointed to figures showing that more than 17 per cent of inmates in federal prisons are double-bunked, meaning two prisoners are being held in a cell originally built for one person.

That figure is an increase of 80 per cent over the past five years.