BHP Billiton advisers have surveyed investors in Rio Tinto about their support for “an alternative” to the heavily-indebted mining group’s proposed $19.5bn cash injection from Chinalco.

Citigroup and Merrill Lynch canvassed the top 20 shareholders in Rio at the end of last week, and told BHP over the weekend that by far the majority of leading investors remained furious with Rio’s plan to raise cash and sell assets to the state-owned Chinese mining group.