National Leader of the All Progressives Congress (APC), Bola Tinubu has in his characteristic manner has criticized  and raised suspicion over the promise by the Independent National Electoral Commission (INEC) that it is doing its best to ensure free, fair and credible elections in 2015. He said the electoral body is deliberately colluding with the Presidency to rig the elections in favour of the ruling Peoples Democratic Party (PDP) through delay in delivery of Permanent Voters Card (PVC).
Source: http://www.ereporter.com.ng/index.php/political-news/item/1161-pvc-inec-colluding-with-presidency-pdp-to-rig-2015-elections-tinubu

I think an allegation like this should be supported with a reasonable evidence of sufficient ground.