Proxy advisory firm Glass, Lewis & Co is telling investors in Zendesk to vote against a planned takeover of Momentive Global, the parent company of web-based surveys Survey Monkey, arguing the company is not well positioned to follow through on the planned deal.

"We believe Zendesk's proposed acquisition of Momentive could readily be characterized as a case of, 'ready, fire, aim'," Glass Lewis analysts wrote in a note, adding, "we recommend shareholders vote AGAINST this proposal."

The report was released to clients overnight and a copy was seen by Reuters. Shareholders will be asked to vote on the deal later this month and many follow the recommendations of Glass Lewis and its larger competitor, Institutional Shareholder Services Inc.

Zendesk agreed to buy Momentive in October in an all-cash deal valued at roughly $4 billion. Investors, including activist hedge fund Jana Partners, quickly spoke out against the proposal, criticizing its financial merit and logic.

Glass Lewis agreed and wrote: "We do not believe Zendesk investors -- perhaps seeking some stability in the wake of the Company's seesawing quarterly performance -- have been afforded persuasive reason to conclude the Company is well positioned to efficiently realize the lofty objectives underpinning the Momentive transaction."

On Thursday, Zendesk said that it had received takeover interest of its own but had rejected a $127 to $132 a share bid and wanted to push on with plans to buy Momentive.