In an unprecedented move, Speaker Mahinda Yapa Abeywardena posted a birthday wish for Minister Namal Rajapaksa on his official Facebook page.

The birthday wish came under criticism from many quarters as the Speaker is expected to maintain his impartiality and independence.

"Although the birthday wish does not violate any stipulated rule, it does not reflect well on the Speaker. He should not have posted that on his Facebook page. This would've been somewhat acceptable had the Speaker posted birthday wishes for every MP in the House," a source familiar with the matter said.

The Speaker's conduct came under severe fire from the opposition last week over his decision to vacate the MP seat of Ranjan Ramanayake.

Opposition Leader Sajith Premadasa and many other MPs in the opposition alleged that the Speaker's conduct was in favour of the ruling party.