Jana Partners owns a large stake in Zendesk (ZEN) and is urging the company to abandon its deal to acquire SurveyMonkey parent Momentive (MNTV), Cara Lombardo of Wall Street Journal reports. Jana urged Zendesk’s board to terminate the acquisition of Momentive now rather than wait months for a shareholder vote that appears likely to fail, Lombardo says, citing a letter sent Tuesday that was viewed by the Journal. The Momentive deal “lacks financial merit, has questionable strategic logic, and introduces a high degree of execution risk for Zendesk shareholders,” Jana wrote. The activist added that it plans to vote its shares against the issuance of Zendesk stock that would be needed to pay for the deal and could seek to replace board members. Shares of Zendesk are up 8% to $102.39 following the report while Momentive is up 1% to $21.27.