Disqualification for joining PTI: no ECP action without party head's reference

The Election Commission of Pakistan (ECP) is unlikely to take action against those parliamentarians who recently joined Pakistan Tahreek-e-Insaf unless the respective political party heads file references against them invoking the defection clauses of the eighteenth amendment of the Constitution of Pakistan.
Jahangir Khan Tareen of PML-F, PML-Q MNA Awais Leghari and his brother Senator Jamal Leghari announced their decision to join PTI at a press conference on December 19. An official of ECP said that defection law of ECP can not be applied on any of the parliamentarian who join PTI until references are filed against them. He added that as yet no references have been received. In the event that references are filed against them, they would be disqualified from contesting the general elections in future.
He said the immediate action against them, if a reference of disqualification is filed against a parliamentarian, would be loss of his seat in the House. "The Chief Election Commission of Pakistan is authorised, under the constitution, to decide the duration of disqualification", the official added.
The Article 63A says, "Disqualification on grounds of defection, etc:
(l) If a member of a Parliamentary Party composed of a single political party in a House­- (a) resigns from membership of his political party or joins another Parliamentary Party; or (b) votes or abstains from voting in the House contrary to any direction issued by the Parliamentary Party to which he belongs, in relation to­- (i) election of the Prime Minister or the Chief Minister; or (ii) a vote of confidence or a vote of no-confidence; or (iii) a Money Bill or a Constitution (Amendment) Bill". The official said that the 18th constitutional amendment further strengthens the head of party leaders and they can file reference against any member of the party in the event of dissident.