Thai King Maha Vajiralongkorn on Thursday signed a new constitution that critics say will give army generals continued influence over the country's politics for years to come.

 The military, in its turn, says the document aims to curb unrest in Thailand's tumultuous political landscape and keep out corrupt lawmakers, as well as putting the country on the path to polls currently scheduled for 2018 - four years after a military coup.

Among other things, it foresees the appointment of an upper house of parliament, and also boosts the powers of the country's constitutional court, making it easier to impeach a civilian leader.

The junta, which took power in a 2014 coup, continues to promise to restore democracy. It has, however, also vowed to draw up a "20-year plan" for the country that all future governments will be obliged to follow.

Analysts say the new charter is redolent of the Cold War-era in Thailand, when unelected bodies and committees had the power to put the brakes on elected lawmakers.

Royal tweaks

The king signed the charter in a televised ceremony in Bangkok on Thursday afternoon. The constitution is now due to be published in the Royal Gazette, after which it becomes law.

Vajiralongkorn, who ascended the throne in December following the death in October of his father Bhimibol Adulyadej, surprised many people earlier this year by ordering parts of the charter dealing with his powers to be rewritten, though what the changes were remains shrouded in secrecy.

Although the constitution was approved at a referendum last August, the junta forbade any political campaigning against it.

Read: Little hope for Thailand's democracy

Keeping politicians in check

Thailand has just experienced a decade of political turbulence, during which there were repeated mass protests that sometimes ended in deadly violence, a series of short-lived governments and two military coups.

Former Prime Minister Yingluck Shinawatra, who was ousted in the most recent coup, said she hoped the new constitution would accelerate the kingdom's return to democracy.

Yingluck is currently on trial for negligence connected with a large-scale rice-subsidy scheme. If found guilty, she could face jail.

Broadly speaking, Thailand's recent political unrest stems from the divide between the mostly poor and rural supporters of ousted premiers Thaksin and Yingluck Shinawatra, and the Bangkok middle class and business elite, who have military backing.

tj/msh (AFP, Reuters)