National Grid bosses have apologised if bailiffs hired by the firm caused "upset or distress" to landowners living along the proposed route of a power line through Shropshire and Mid Wales.
And they say they have now reviewed how they are carrying out the process of getting access to land.
Wales First Minister Carwyn Jones has promised an investigation after complaints that residents had been verbally abused by bailiffs delivering land access notices.
Montgomeryshire MP Glyn Davies, Welsh Assembly Member Russell George and Llansantffraid Community Council have all voiced concerns after complaints of abuse from residents in the Vyrnwy Valley.
Jeremy Lee, project manager for National Grid, said: "Our first aim is always to work with landowners to request access voluntarily, and many people have agreed this, which we're very grateful for.
"Others, however, have not wanted to agree. We recognise that people are concerned about the proposals and don't want them to go ahead, but it's important we complete all of the necessary assessments if we're to develop the connection as sensitively to the local area as possible.
"We've given landowners several opportunities to confirm details of their ownership and agree access.
"For those who haven't, we are now having to use our statutory rights to seek access and have started this process.
"This is always our last option, but is a process we feel we have to use to give communities certainty on how and where the connection could be built.
"This work is always undertaken professionally and politely and there is no benefit to us to upset or distress people and we apologise if we have done so. Quite the opposite, our desire is always to work closely with landowners so we complete work with the minimum of inconvenience."
The alleged behaviour of the bailiffs was raised at a meeting of Llanfyllin Town Council when Mr Lee spoke to councillors.
Councillor Peter Lewis said: "There is a lot of concerns about what is happening when serving notices on landowners to get access to the land and the manner of using bailiffs is quite intimidating.
"How can you let this happen?
"They are intimidating people, making people physically sick. People are scared of these people going around."
National Grid is proposing to build the line from a substation at Cefn Coch near Llanfair Caereinion to Lower Frankton near Oswestry so electricity generated by proposed windfarms in Mid Wales can be carried to the national network.