Northland-based Labour list MP Shane Jones said he was concerned about the notion of a fence and security guards stopping people sneaking into the birthplace of the nation.
``The suggestion that swarms of foreigners are sneaking in is ridiculous. Probably a few do, but having a fence changes the tone and openness of the place,'' he said.
Mr Jones conceded the Trust had a genuine dilemma and had to be innovative to pay for upkeep. Given the significance of the site in the nation's history, it seemed odd the nation wasn't making a contribution.
When Helen Clark was Prime Minister in 2007 the trustees had a chance to engage with the Crown to receive a regular contribution to help meet their day-to-day costs. However, Mr Jones said that was seen as an ''intolerable threat'' to the trust's independence and the conditions set by Lord and Lady Bledisloe when they gifted the grounds to the nation in 1932. He did not recall any strings attached to the offer of help.
Waitangi National Trust chairman Pita Paraone said the Treaty Grounds did not receive government or local body funding, unlike regional museums.
''We have no difficulty with that, but it does make it challenging. We are trying to run a business and we just want a fair slice of the tourist dollar.''
The fence had been planned for several years so it only coincidental it was going up after the appointment of a new chief executive, former Rotorua Museum boss Greg McManus.
It was designed to be unobtrusive and in places, such as near the Hobson monument, people might not realise it was there. Mr Paraone urged anyone with concerns to contact Mr McManus.
In 2008 political pressure from Mr Jones, among others, led the trust to drop what was then a $12 entry fee for New Zealanders. To compensate, the fee for overseas tourists was lifted to $20 and then $25.