NDP leader Jack Layton says the public ought to have a say in how the government plans to spend a massive budget surplus now pegged at $6.4 billion.

Layton is calling for a parliamentary debate over the surplus, which the Finance Department revealed Friday is now double what was initially projected.

He is urging Prime Minister Stephen Harper not to simply inject the funds into paying down the national debt -- something both he and Harper criticized the Liberals for doing when they were in power.

Layton says hardworking Canadian taxpayers are responsible for the surplus, yet many are struggling to support their families.

He believes the surplus should be spent on foreign aid, affordable housing, public transit and keeping post-secondary education fees down.

Layton also wants the government to fill the vacant parliamentary budget officer post created a year ago under the Federal Accountability Act to oversee the management of large budget surpluses.