Eirgrid is being called on to explain claims it has "good relationships" with landowners along the North South Interconnector route.
In a letter to Monaghan County Council, CEO Mark Foley said landowner and community support for the powerline is a key focus for the company.
An expert review of the contentious project is to get underway shortly, with Eirgrid expecting construction to begin in late 2022.
However, local politicians and community groups are against the Interconnector going ahead with overhead pylons.
Sinn Fein's Noel Keelan says he's sceptical about how many landowners are on Eirgrid's side.