Myanmar rebel groups and their long-time government foes are on the verge of sealing a ceasefire deal that supporters hail as historic but critics attack for falling short of hopes kindled by protracted talks.

Political leaders, fighters and diplomats will gather on Thursday in Naypyidaw, the former military junta’s purpose-built capital, to ink an agreement billed as a “nationwide ceasefire” to which only eight out of 15 regional movements have signed up.

The deal’s backers say it is a crucial foundation that can be built on after landmark elections next month into a full-fledged peace process to end more than 60 years of civil conflict. But sceptics say the organisations that are signing are already in formal or de facto ceasefire agreements, while groups in active conflicts in more northern regions near the Chinese border have held back.