CM Punjab Mian Nawaz Sharif has said he has extended invitation to join Punjab cabinet to the Prime Minister and that PML-N to welcome Pakistan Peoples Party if it decides to become part of the Punjab government. Talking to media on the occasion of wedding of MPA Syed Rafiuddin, he said Mian Nawaz Sharif has written a letter to the Prime Minister in which it has been recommended that a national conference be convened for devising a strategy to pull the country out of the present crisis.