Another top proxy advisor has recommended shareholders vote against Elon Musk's $56 billion Tesla pay package

• Institutional Shareholder Services recommends Tesla shareholders vote against Musk's huge pay deal.
• It comes after Glass Lewis, another proxy advisor, made the same recommendation.
• Investors will vote on the $56 billion package at Tesla's annual meeting on June 13.

Influential proxy advisor Institutional Shareholder Services (ISS) has recommended that Tesla shareholders vote against Elon Musk's proposed $56 billion pay package.