Tonga's public servants, who have just ended 44 days of strike action, are expected to join pro-democracy marchers in Nuku'alofa tomorrow.
The workers have gone back after the Government on Saturday gave in to their demands for wage increases of up to 80 percent.
But Finau Tutone of the Interim Public Servants Association says the workers will be able to take casual leave tomorrow to march.
He says the march, which is expected to attract thousands, will focus on the workers demand that a Royal Commission into the constitution be set up and that the Prime Minister, his Cabinet and key officials be sacked.
"And for the king, in the platform of the current constitution, to have or to appoint an interim government for one year and let the Royal Commission or some of the representatives to work to make the constitution more democratic."