Recent reports had written off the chances of the Holidays (Full Recognition of Waitangi Day and Anzac Day) Amendment Bill but Dr Clark said he had received pledges of support from United Future and the Maori Party - Government allies - along with all Opposition parties.
He told the Otago Daily Times yesterday he expected the Bill to pass 61 votes to 60, meaning the legislation would go through to a select committee.
The Bill corrected an anomaly that happened roughly twice every seven years. When this glitch happened, New Zealanders missed out on the usual full complement of 11 public holidays, he said.
"For the folk who work Tuesday to Saturday, or Wednesday to Sunday, they miss out on the Monday holidays. This Bill won't solve that problem.
But we will get a chance to hear from people on a wide range of issues.
"Clearly, people think this is a sensible idea."
The Bill was not going to impose a burden on employers and was not fiscally irresponsible, Dr Clark said.
Information he received under the Official Information Act suggested there would be benefits to the economy from the Monday-isation of the holidays.
"One of the industries that will benefit is domestic tourism.
Prime Minister John Key is the Minister of Tourism but he is the Grinch opposing this Bill.
"This is one plum thing he can do for the tourism industry that doesn't cost a lot of money yet he is not supporting the very industry for which he is minister."
The costs incurred by Monday-ising the de facto national days were already accounted for by employers, he said.
