Dhaka, April 9 (IANS): Two weeks after making a startling claim that Ziaur Rahman was Bangladesh’s first president, senior BNP leader Tarique Rahman said Bangabandhu Sheikh Mujibur Rahman was an "illegal" prime minister.

Rahman made the comment at a function, organised by the Bangladesh Nationalist Party (BNP) at the Westminster Hall in London Tuesday, bdnews24.com Wednesday reported.

He said Sheikh Mujibur Rahman was the "first illegal prime minister of Bangladesh" as he had apparently defied the declaration of independence made April 10, 1971, when the first government was formed.

"So, how does Sheikh Mujib take oath as the prime minister Jan 12, after returning to Bangladesh Jan 10? The constitution was yet to be prepared then," said Tarique, who is living in London since 2008.

The BNP leader came down hard on Bangladesh Prime Minister Sheikh Hasina, saying she was holding on to power illegally, just like her father had done.

“The harsh truth, which may be unpleasant, has to be brought to light for the sake of history,” he said.

Sheikh Mujibur Rahman is regarded as the founding father of Bangladesh.