The flagbearer of the opposition New Patriotic Party has thrown a challenge to President John Mahama to reopen tender on the famous Kasoa interchange project which he believes is fraught with corruption.

Nana Akufo Addo is convinced the project estimated at some $172m has been over bloated and could have been completed at half the price.

He said the Kasoa interchange project is one of 21 projects being undertaken by the government and which costs have raised several eyebrows.

"Check the [Kasoa] figures; check them again" Akufo- Addo threw the challenge to Mahama while addressing the second Aliu Mahama memorial lecture, adding even if an independent open tender will be invited, the president should do it and see if the country can't save half of what has been estimated.

He said while the President has the power to ignore his challenge it will be an "unprecedented show of strength" and not weakness if he should take him up on the challenge.

"He [Mahama] has nothing to lose," he added

Only then will the President demonstrate to all, a clear commitment to fighting corruption.

Nana Akufo Addo was speaking on the theme "One Ghana, securing our future."

He said, "if we are to secure our future, we must first secure our public purse" which for now is being depleted on numerous dubious projects.

"Corruption will destroy the country," he stated, and called on the leadership of the country right from the president, ministers, judges magistrates to demonstrate a clear commitment to fighting corruption instead of the pious declarations that are currently being made.