Former Thai prime minister Yingluck Shinawatra on  sought a blessing by Buddhist monks' blessing at her house in Bangkok on Wednesday ahead of a court verdict due on Friday that could land her in prison.

Yingluck invited 17 monks to her house to give alms - a tradition in Buddhist-majority Thailand, before visiting another temple in Bangkok to release captured fish back into nature for good luck, her spokesman said.

Thailand's first and only female prime minister, Yingluck was charged with criminal negligence for her administration's controversial rice subsidy programme that allegedly cost the country 8 billion dollars in losses according to the ruling military government.

Her 18-month trial will come to a close with a verdict on Friday. If found guilty, she could face up to 10 years in prison and be disqualified from becoming prime minister again.

A prison sentence would also mean Yingluck might be the first former premier in Thailand's history to be put behind bars, pending an  appeal application and a possible suspended sentence.

Yingluck's brother, former prime minister Thaksin Shinawatra, was sentenced in absentia to two years in prison for land corruption in 2008, but he remains in a self-imposed exile to evade conviction.

If found guilty, Yingluck can appeal the case 30 days after the verdict is read, Jetn Sirathranont, a parliament spokesman, told dpa.

During her appeal process, Yingluck can still apply for bails and travel outside the country, Jetn added.

Yingluck's verdict is set to deepen Thailand's political conflicts as her popularity remains strong among the working class and rural population in the north and north-east. Should she be convicted, this could make her a martyr under military rule, analysts say.