The Pilgrims boss left the club yesterday, with Newton confirming the parting of ways was 'the club's decision'.
"Probably the toughest I've made in the last 14 years," Newton said.
"He's a top man, top manager. Hard working, decent and I can't speak highly enough of him obviously."
Elliott's four-year tenure has seen him guide the Pilgrims from the relegation zone to a National League North play-off final and the FA Cup's second round, before a replay defeat to then-League One Rochdale.
Despite another Covid and injury-hit season, which also saw Elliott lose three first team players to gambling bans, Newton felt it was time to make a change.
"Probably results and performances over the season," he said, when asked why the decision was made.
"Not the expectations he or us wanted, to be fair.
"Clearly there's lots of mitigating circumstances this season. Overall we felt it was probably time for a change."
Of course, there will be plenty of interest in the role as the Pilgrims sit seventh in the National League North.
Newton's phone was ringing 'within seconds' of yesterday's announcement, as hopefuls threw their hat into the ring.
The club confirmed they will be seeking applications for the role, suggesting no deal has been done with a replacement prior to Elliott's departure.
United head to Gloucester City on Saturday with Newton adding an announcement about who will be leading the take is expected to be made later today.
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