The Andrews government could be heading for a serious industrial clash with 40,000 public servants demanding an extra week off work each year on top of a 3.5 per cent pay rise and boosted superannuation.

The public servants say the extra time off would reflect the large amounts of unpaid overtime they already perform and help families cope with the demands of a four-term school year.

The public servants want an extra week's holiday. Credit:James Davies

The government workers are determined to see a pay increase of at least 3 per cent, putting them on a collision course with Treasurer Tim Pallas, who has already flagged his intention to limit pay rises to 2 per cent.

A few months of tough negotiations loom at the end of the year, with the two sides a long way apart on core wages and conditions.