Air China’s parent company on Sunday night escalated its campaign to prevent Singapore Airlines investing in domestic rival China Eastern (CEA), saying it would offer at least 32 per cent more for the shares if investors rejected the Singaporean bid.

The announcement increases the chances that shareholders will reject at a meeting Tuesday an agreed offer by Singapore Airlines and Temasek, the country’s state investment agency, to pay HK$7.16bn ($917m) for a 24 per cent stake in CEA.