Please help me with the below question!

You are a Project Manager of Payroll implementation application and the project is governed via Matrix organization, comprised of functional leaders from IT, Finance, and HR and you report to PMO. The scope of the project is the implementation of the application within the organizations data center, and only includes payroll and workforce management too. There is a growing opposition from IT and Finance to switch to the cloud which would provide them also with customized Business Intelligence reporting at no cost.

You are the Project Manager, but the influential department leaders are refusing to support and provide funding unless you switch to cloud, the COO who is the executive sponsor wants this dispute to be resolved ASAP and move forward with the project (2-weeks delayed).

What will you do as a PM?