A breakdown of the figures indicate up to 600 more Wanganui residents were out of work by the end of September, compared to the previous quarter, or 9.4 per cent of the available workforce.
Ministry of Social Development data show the number of people on the unemployment benefit in Wanganui during that same period rose by just 48.
A Ministry spokesperson said not all those who had become unemployed in the three months to September would have immediately registered for the dole.
Engineering, Printing and Manufacturing Union organiser Colin Webster said it was time the Government "pulled its head out of the sand".
Mr Webster said employees and employers were struggling to cope with the economic conditions.
"Tax cuts would put more money in people's back pockets, which they spend and inject into the local economy," he said.
Mr Webster was not aware of any recent redundancies at the Wanganui-based firms he oversaw, including Axiam Metals, Mars Petcare and Tenix.
He said Wanganui was prone to seasonal fluctuations in employment. The downturn had led many employers to make use of casual labour, rather than taking on permanent staff members, and this also had a marked impact on the swaying unemployment rate, Mr Webster said.
The increase in unemployment was particularly noticeable in other parts of the country, too.
In Auckland it was at its highest level in two years.
There were also big increases in Bay of Plenty, Wellington, Otago and Southland, while Canterbury fell to 5.2 per cent.
Maori unemployment continued to rise, it was at 15 per cent by September.
Pacific unemployment was also at 15 per cent, compared with 5.4 per cent for Europeans.
Maori Party co-leader Tariana Turia said: "Some of the evidence that's come out is really against employers who won't give young Maori people a chance, and yet we were told that the ... 90-day trials would give employers the opportunity to try these young people out."
Whanganui MP Chester Borrows said work-readiness programmes and subsidies for employers who took on the unemployed were measures the Government was using to address unemployment.
He said the 90-day probationary period for new employees and the "starting-out" wage scheme, where 16- to 19-year-olds could be paid no less than 80 per cent of the $13.50 minimum wage rate for no more than six months, encouraged employers to take on young and less-experienced staff members, "where previously all the incentive on employers was to give older and more-experienced workers a job".
Mr Borrows said Wanganui was significantly affected by seasonal employment.
"And as we enter exam periods in schools and tertiary institutions there are more looking for work," he said.