Former Punjab chief minister Amarinder Singh on Tuesday said Navjot Sidhu’s resignation as PPCC chief within two months of taking over the vital post had proved beyond doubt that the cricketer turned politician was an “unstable” man, who could not be relied upon to lead the ruling party, especially in a border state like Punjab.Former Punjab chief minister Amarinder Singh on Tuesday said Navjot Sidhu’s resignation as PPCC chief within two months of taking over the vital post had proved beyond doubt that the cricketer turned politician was an “unstable” man, who could not be relied upon to lead the ruling party, especially in a border state like Punjab.