Nepal was pushed further into a political turmoil over a draft of a new constitution with an opposition alliance vowing street protests.

The opposition was angered by the parliament speaker announcing Sunday a governing parties-backed proposal committee that would proceed with voting on the constitution.

The opposition parties are demanding the draft be prepared by consensus and not just by the ruling coalition that has an overwhelming majority in the assembly.

Security was stepped up Sunday in parliament with rows of security personnel blocking the protesting opposition members when Speaker Subash Nemwang made the announcement.

Nepal has struggled to draft a new constitution since 2008.