BJP president Nitin Gadkari on Friday said Prime Minister Manmohan Singh and UPA chairperson Sonia Gandhi should apologise to the nation for the ‘political conspiracy’ under which BJP whistle-blowers were jailed in the cash-for-vote scam. Addressing a Press conference here, Gadkari, who is on a day’s visit to the city, alleged the Congress had purchased 19 MPs to save UPA-1 during the trust vote in July 2008. Gadkari said though Singh enjoyed the image of being a clean person, it was impossible that people could be sent to prison without his knowledge or consent.