The public sector union says big IT glitches in government systems are the result of “chronic underfunding”.

The Bureau of Meteorology website was hit with a “physical networking issue” late last week, which blocked all updates to the site while several bushfires burned around the nation.

While the problem was fixed within hours, the Community and Public Sector Union says it is just the latest in a pattern of “computer glitches” emerging across Commonwealth systems.

The issues at BoM came just days after Centrelink blamed a “computer glitch” for sending messages to 73,000 families, telling them they had to repay money owed on their family tax benefit accounts.

Some clients told Fairfax that their accounts were changed to suggest they owed thousands of dollars.

CPSU National President Alistair Waters says there is “chronic underfunding” across the federal government IT systems.

“These computer malfunctions at Centrelink could not come at a worse time of year, given the extra financial pressure many families are under over the Christmas period,” the union official has told reporters.

“[Centrelink] Workers care deeply about their clients, and our members are sick of governments failing to provide the tools and staff numbers needed to deliver the excellent service the community deserves.”

“It's little surprise that customer service standards have eroded so much over recent years.

“The Government has refused to invest in IT systems while cutting staff numbers and turning to an increasingly casual workforce.

“The problems with the Bureau of Meteorology website are also a cause for concern, especially given the important information provided for people facing potential disasters such as bushfires and flooding at this time of year,” he said.

“We have members of the government... boasting that the number of people working in the public sector has been cut back to 2006 levels, while ignoring the fact that Australia's population has grown by more than 3 million people who expect decent services from Centrelink, BoM and other agencies.”