National Party MP's have overwhelmingly spent the most money on accommodation and travel

Between July and September six MPs managed to rack up nearly 140-thousand dollars in expenses.

The biggest spender was social development spokesperson Louise Upston - at more than 32-thousand dollars.

But Auckland University political expert Lara Greaves doubts it'll come back to bite them.

She says people generally expect politicians to spend many on things we don't deem necessary - but we value their privacy.

The Green Party spent double what the Labour party did on air travel over the same period.