The Ukrainian government has made an extraordinary intervention on behalf of Turnbull government MP Chris Crewther, arguing a proposed boundary change to his marginal electorate would disadvantage a Ukrainian cheesemaker.

Mr Crewther, who first won the Melbourne seat of Dunkley in 2016 by just 1.4 per cent, is fighting the proposed changes. ABC election analyst Antony Green predicts the new boundaries would turn the seat notionally in favour of Labor by a margin of 1.3 per cent. The seaside town of Mornington, in Dunkley's south, is one of the areas slated for removal under the Australian Electoral Commission's suggested new boundaries.

Mr Crewther has been urging supporters, including the Ukrainians, to make submissions to the AEC protesting the changes.

In a letter to the AEC, Ukraine's ambassador to Australia Mykola Kulinich said he was "extremely concerned" about the proposed changes, and warned that the Ukraine-Australian relationship would "only be strengthened by Mornington remaining within the Dunkley electorate."

"I believe that the Ukrainian community in Dunkley will be disadvantaged by separating Mornington from the electorate, where many reside," the ambassador said.