Bangkok: The military junta that overthrew former prime minister Yingluck Shinawatra last year has swung to the side of Thailand's royalist establishment and Bangkok middle class, reviving a bitter power struggle in the country after months of fragile peace.

Ms Yingluck, 47, declared that Thailand's democracy is dead after a military-stacked parliament, described by her supporters as a "show trial," impeached her and the attorney-general indicted her on criminal charges that could see her jailed for up to 10 years.

Soldiers guard outside the Parliament of the National Legislative Assembly as members voted to impeach ousted former prime minister Yingluck Shinawatra. Credit:Reuters

"Democracy has died in Thailand today, along with the rule of law," Ms Yingluck wrote on her Facebook page, adding she will fight to the end to prove her innocence.

"That move to destroy me is still ongoing and I face it now," she wrote, appearing to defy orders by the country's ruling generals not to criticise them.