MPs expenses appear to show Todd Muller has been campaigning for months to roll Simon Bridges

It appears National Party leadership hopeful Todd Muller has been campaigning for months to roll Simon Bridges. 

MPs' expenses out today show a massive increase in Muller's travel and accommodation costs over the last three months, spending a whopping $34,528 in three months. 

It's up by $11,400 on the previous quarter. 

Muller has been touring the country with his surface travel costs doubling from $5999 between October-December 2019 to $11,848 between January and March this year.

He's also more than doubled how much he spent on accommodation out of Wellington from $1354 to $3324. 

Muller is leagues ahead of other MPs in terms of how much they've spent, with the next highest being Rotorua MP Todd McClay on $27,118.

Party leaders always spend the most, but Muller is just $2655 off Simon Bridges' expenses of $37,183 - and his include crown limo costs, so should be way more. 

Regional MPs' expenses are always higher but Muller is from the Bay of Plenty, the electorate neighbouring Bridges' Tauranga seat. 

In 2018, the leaking of MPs' expenses caused one of the biggest political scandals in modern politics after Bridges spent up large on crown limos. 

Muller told Newshub it was not about campaigning but meeting with farmers - part of his role as National's agriculture spokesperson.

When Newshub asked if he had met any MPs on those trips, he said, "There would probably be a few, but the main focus was always farmer meetings - I could get up to six a day from different farmer meetings around the country.

"The surface travel tends to build when you do that, but that's the driver for it."

Bridges would not comment for this story.