Other big banks are following Westpac's lead of hiking up mortgage rates because they know the prime minister has their back, Labor says.
Commonwealth Bank and ANZ on Thursday became the latest major banks to lift their home loan interest rates, with both institutions blaming rising international borrowing costs.
Labor finance spokesman Jim Chalmers says the banks are taking advantage of the chaos in the Liberal Party and knowing Scott Morrison will "always side with them over people who work and struggle".
Australians have good reason to be frustrated with the big banks and will be taking their business elsewhere, he said.
"Middle Australia is already struggling to make ends meet, and customers of the big banks will be considering other options."
Westpac last week became the first major bank to reveal its variable home loan rates would go up, due to its wholesale funding costs rising.
Mr Morrison said at the time Westpac needed to justify the change to its customers, and suggested they shift banks if they didn't like the explanation.
"If you don't like what Westpac's done, go to another bank," he said.
Westpac's variable home loan rates will go up by 14 basis points from September 19.
ANZ will lift its standard variable rate by 16 basis points from September 27 but the increase won't apply to drought-affected regional customers.
CBA's standard variable rate for owner-occupier borrowers will go up 15 basis points on October 4.
