The National Democratic Congress (NDC) says it is worried by the irregularities being experienced at many polling centres across the country.
At a news conference, Elvis Afriyie Ankrah, Deputy General Secretary (Operations) said many polling stations were without transfer voters' register and officials were allowing persons to vote only with the transfer slip.
Mr Ankrah said the anomaly opened the electoral process to abuse since everyone with a slip could go into polling centres to vote, irrespective of the constituency to which they had transferred their votes.
The NDC is also worried about the delay in the commencement of voting at the Dwarf Island in the Afram Plains, where at 1230 hours there was no trace of electoral officials and voting logistics.
"Considering that the Dwarf Island was left out in the Special Voting we hope they are not going to be disenfranchised again," Ankrah said.
There was also concern about the development in Ntowkrom in the Assin North Constituency, where presidential ballots are being given to voters unstamped.
Mr Ankrah said NDC polling agents were also being prevented from affixing the NDC's seals on the ballot box as agreed with the Electoral Commission.
He cited Kwadaso in the Ashanti Region, Ablekuma South (Korle Bu Teaching Hospital Midwifery Training School in the Greater Accra Region) and Suhum (GCB shed No E 071402) in the Eastern Region.
Mr Ankrah urged NDC supporters to remain calm, vigilant, resolute and resist the provocation to be violent.
"We are confident of victory and we respect the verdict of Ghanaians so let us not do anything that will mar this beautiful exercise," he added.