Wickremesinghe made the remarks while presenting the reports of six sub-committees to the Constitutional Assembly.
The sub-committees were appointed to look into matters pertaining to the new Constitution. The sub-committees deliberated on different areas of Constitutional provisions and will report to the main Steering Committee.
Leader of the Opposition and Tamil National Alliance (TNA) leader R Sampanthan also said the Constitution needs to be approved in a nationwide referendum.
He said people must be given the chance to take part in the process and "people must be asked to approve it (Constitution)".
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The government expects the new Constitution to address the demand of Tamil minorities for political recognition.
With the defeat of the Tamil Tigers in 2009 the Tamil groups have opted for maximum devolution as opposed to LTTE's goal of a separate Tamil homeland.
Wickremesinghe, while presenting the reports, also voiced support for the Constitution to be finally approved by the people. He said the final form of the constitution was yet to be determined and one of the contentious issues was the position of the executive president.
"No party has a majority in the House so this will have to be an all political party effort and at the end of it we will give people the chance to approve it," he said.
Leader of the Joint Opposition Dinesh Gunawardana said their group had submitted a 14-point plan. He asserted that they would not agree on diluting the unitary nature of the state or diluting the position given to the majority religion of Buddhism.
"We would not agree to any bulldozing of the process. Things must not be done in a hurry," he said.
A 21-member steering committee consisting of parliamentarians from across all political parties has been set up.
The government's Constitutional reform process began in January this year. The whole Parliament was converted into a Constitutional assembly with cross-party participation.