Members of Berwick Borough Council's planning committee went against their officers' advice in granting permission for the change of use of land at Marshall Meadows Farm to provide extra space at the existing caravan park.
Councillors were told that although the area was not part of the Area of Outstanding Natural Beauty, it did form part of the Northumberland Heritage Coast.
In recommending refusal, officers said this meant any extension to the caravan site would have an adverse effect on a nationally important coastal landscape.
Committee chairman, Coun Brian Douglas, declared an interest in the item, and retired to the public gallery from where he spoke in favour of the proposal before leaving the chamber while remaining members made their decision, vice-chairman, Coun Richard Patterson taking over.
Coun Douglas said that during his lifetime, the farm on which the caravan park was situated had been forced to diversify in order to secure its future.
He said at one time the farm had been one of the largest dairy producers in the area, but no longer had any cattle.
Owned by the Fairbairn family, the farm covers 180 acres, almost all in pasture with poor grades of soil, Coun Douglas told the committee.
In addition to the caravan site, other activities carried out included a landfill operation, transport and construction hire business and stone crushing facilities, plus the breeding of heavy horses.
"The caravan site makes a significant contribution to the local economy in attracting caravan owners to Berwick at a very competitive rate and the site helps sustain business to the Marshall Meadows Hotel," he said.
Coun Douglas added that the park catered for an older crowd which appreciated the beauty and tranquillity of the surroundings.
"The owners have upgraded the site at their own expense with a new sewerage scheme, roads, concrete bases and a small play area, without any financial grant assistance.
"The Fairbairn family are committed to continue farming at Marshall Meadows and to support that commitment I would request members support approval of the application," added Coun Douglas.
The committee was told the plans would see an additional 48 static caravans placed in the park on top of the existing 90 units, with man-made two-metre high earth mounds to provide screening.
The scheme had been scaled back from an application submitted last year for an additional 65 caravans.
Councillors were told that in the officers' opinion, the extension was considered a substantial development which would push the presence of caravans into an open, undeveloped and exposed cliff top area, although it was conceded there was some merit in the way the plans set out the arrangement of the caravans.
Refusal was recommended on the grounds that the extension was at odds with both the Local Plan and national planning policy guidelines.
Concern was also expressed at the proposed man-made screening mounds, but Coun David Donaldson pointed out that similar mounds had been constructed at other sites within the Area of Outstanding Natural Beauty at Waren Mill, near Beldford.
"This is a much less sensitive area than that," he said.
Coun Lance Robson asked if a condition could be put on any approval that the caravans were coloured in such a way as to blend in with the surroundings.
Coun Dougie Watkin added: "Given the right landscaping and conditions, it can be acceptable, alongside what is already there."
He proposed that permission be granted, and was seconded by Coun David Wilson. Committee members voted 5-1 in favour of granting planning permission.