Several political parties in Pakistan, including the ruling PML-N, have called for an investigation into the alleged horse-trading in the crucial Senate elections.
Last week, Pakistan Muslim League-Nawaz (PML-N) of ousted prime minister Nawaz Sharif won 15 seats in Senate and became the largest party in the upper house of Parliament, according to the provisional results.
Provincial and federal lawmakers voted to elect 52 Senators in the Senate elections, according to the Election Commission of Pakistan (ECP).
The election outcome has been marred by charges of horse-trading.
Sharif blamed those political parties that secured more seats than their representation in the provincial assemblies for "rigging the Senate elections" and demanded an investigation to ascertain if the change of loyalty was based on change of mind, financial gain or some other factors, Dawn News reported.
The former prime minister said the game of trading of votes must come to an end.
The same demand was made by Pakistan Tehreek-i-Insaf chairman Imran Khan on the second day of his two-day visit to Karachi.
Khan said according to his information, votes were purchased for up to Rs 40 million in the elections.
"Our own people also sold themselves," he admitted but did not mention names of those allegedly involved in the practice in Khyber Pakhtunkhwa and Punjab assemblies.
He said his party had been asking the Election Commission of Pakistan to replace the old secret ballot system with open voting for Senate elections to help check corrupt practices, but the ECP did not accept the demand.
It was for this reason that the lawmakers had indulged themselves in trading of votes, he alleged, while asking the ECP, National Accountability Bureau and Federal Investigation Agency what actions they had taken to check the horse-trading.
The PTI chief demanded that Chief Justice Saqib Nisar take notice of the horse-trading, explaining that those who had bribed the lawmakers were known but the legislators who had allegedly taken bribe to switch loyalty were not traceable.
Also the Muttahida Qaumi Movement-Pakistan (MQM-P), which suffered a major setback in the election, announced that it would challenge the Senate elections in the ECP and courts accusing Pakistan Peoples Party (PPP) and Pak Sarzameen Party (PSP) of "harassing" MQM lawmakers and "selling" the mandate of Karachi.
While addressing a press conference, Farooq Sattar, heading the PIB faction of the MQM-P, said the Senate elections lost credibility as they were not held impartially and transparently.
He alleged that the PPP harassed more than 15 legislators of his party in order to pressure them to change their loyalty. He accused PSP chief Mustafa Kamal and his deputy of "selling" the mandate of Karachi.
The election results for 12 Senate seats from Sindh have surprised many. Farogh Naseem, who supports the Khalid Maqbool Siddiqui-led faction of MQM, is the only candidate of the party to have emerged victorious for the upper house of the parliament.
Just a day ago, Jamaat-i-Islami chief Senator Sirajul Haq, too, had demanded investigation into the allegation of horse-trading. He also appealed to the chief justice to take notice of the Senate election where parliamentarians allegedly cast votes for financial gains and other benefits.