Labor has continued to pressure the government over regulatory changes at Australia Post, saying it will lead to one in four postal workers losing their jobs.
Australia Post and Communications Minister Paul Fletcher has waved off the concerns.
"You know that there's a by-election on when Labor turns to the odd scare campaign," Mr Fletcher told parliament on Friday, days out from early voting for the NSW seat of Eden-Monaro.
The coronavirus pandemic has seen an explosion in parcel delivery and a sharp drop in letters.
Thousands of motorbike posties were being redeployed into delivery vans or warehouses.
Priority letter services have been suspended, letter deliveries moved to every second day, and five days is being allowed for intrastate posting.
Earlier in the day Labor lost its bid to force parliament to block the regulatory change, with party leader Anthony Albanese gagged by the government.
He asked Mr Fletcher if he had considered what effect the cuts to letter delivery would have on older, isolated Australians.
"(They) rely upon postal services to stay in touch with their families and friends," Mr Albanese said.
Mr Fletcher said the changes were meant to help Australia Post cope with the increased demand.
"If Labor succeeds in overturning this temporary regulatory measure it will disadvantage the very people they claim to protect," he said.
Earlier this week, the Communications, Electrical and Plumbing Union called on parliament to block the changes.
It claimed one in four jobs would go and workers would see a reduction in pay.
Australia Post said there were no plans for redundancies or pay cuts.
Australian Associated Press