"Rotorua is a very popular tourist destination and Easter is one of our busiest weekends," Mr McClay said.
"Both Steve and I have previously brought Bills before Parliament and whilst this is a conscience vote, so far Parliament has clearly been split along party lines," he said.
In 2003 Mrs Chadwick sponsored a Local Bill which was defeated by 63 votes to 55.
In 2007 her second attempt with a Member's Bill was rejected by 64 votes to 57.
Then in 2009 Mr McClay's Easter Sunday Local Choice Bill narrowly missed being passed by just two votes.
Mr McClay said Mrs Chadwick's Bills were primarily supported by Labour MPs and his proposal received equally strong support from National MPs.
But neither MP received significant support from the opposing party.
"This suggests to me that there is enough support in Parliament to bring about change for Rotorua and I firmly believe that Mayor Chadwick and I will be able to convince MPs across the house to put aside party politics and focus on supporting Rotorua," Mr McClay said.
Mr McClay said draft legislation was likely to be a Local Bill presented to Parliament by the Rotorua District Council and sponsored by him as local MP.
"Local shopkeepers should be able to choose to open their shops, local workers choose to work should they wish and visitors choose to shop whilst on holiday in our city."
Mrs Chadwick said there was no real logical reason for Rotorua to be treated differently from Queenstown and Taupo.
"All we are asking for is a level playing field," she said.
"While Todd and I come from different political backgrounds we are united in wanting to get some legislative changes to the existing trading restrictions so our business community can also enjoy the freedom to trade at Easter, if that's what they want to do.
"We owe it to our Rotorua community to do whatever we can to ensure the interests of our local businesses, our visitor industry and our local residents are protected.
"I'm hoping that common sense will prevail and that central government will see that cities and towns like ours need to be given the opportunity to decide as local communities whether to allow Easter Trading," she said.
Rotorua Chamber of Commerce vice president Meryn Morrison said the chamber supported the move.
"Rotorua is clearly a destination stop for many varied activities over our Easter weekend. Tourists' demands have changed to wanting a whole package experience and it's up to our local businesses to offer the lifestyle choices to support sporting, leisure and spa activities over this long weekend.
"The Rotorua Chamber of Commerce supports our local businesses to be allowed to choose whether to offer a service by being open or not. "They should have that choice," she said.