The statement on page 55 of the manifesto contradicts promises given last autumn that while the Government would do all it could to protect endangered species by tackling poaching, it would not seek to put an end to the trade in antique items containing ivory. Under CITES (Convention on International Trade in Endangered Species) rules, the trade in worked ivory dating to before 1947 is legal.
However, after ATG approached Conservative Central Office for clarification, a spokesman confirmed that the policy would now be to achieve a total ban.
"In pressing for a total ban on ivory sales we will work with our international partners and interested parties at home to see how best to achieve this and over what time frame," said the spokesman.
"We recognise the importance of the UK art and antiques trade and will be discussing this issue with them in more detail."
British Art Market Federation (BAMF) chairman Anthony Browne declared the manifesto pledge "baffling, having had complete assurance from DEFRA [Department for Environment, Food and Rural Affairs] that this would not happen".
"We were very surprised to see this manifesto commitment by the Conservatives, which appears to represent an abrupt U-turn from their previous policy," he told ATG.
"Ministers have confirmed to us on many occasions that they recognised and respected the clear distinction between the illicit market for ivory and the legitimate ownership of antique cultural objects and the market for them, and they have always supported the legitimate market."
The impact would be widespread, he said. "While we welcome the Conservative Party's acknowledgment of the importance of the British art and antiques trade, which directly supports over 40,000 jobs, there should be no doubt that an unqualified ban on the trade in all ivory, regardless of its age, would have a profoundly damaging effect on many businesses in the art market.
"Further than that, it would affect anyone who owns an heirloom made from, or containing, ivory - musical instruments, miniature paintings on ivory, furniture with ivory keyholes or inlay, teapots with ivory finials, early carvings. The list is long. These would become unsaleable under such a ban."
"Smacks of Maoism"
Dealer Martin Levy of H Blairman & Son said: "There is universal support for the protection of endangered species, not least the elephant. But demonising works of art that happen to be made of, or contain ivory, is to cut us off from our shared cultural past.
"It is smacks of Maoism for a political party to wish to deprive owners of their freedom in relation to treasured artefacts, often handed down as heirlooms - and this from the Conservative Party.
"The art market is totally behind the NGOs' fight for the elephant. Let these organisations recognise our support, and at the same time express publicly what is obvious: there is no correlation between a 17th century baroque ivory cup, and the illicit trade in poached tusks - none."
Paul McManus, chief executive, Music Industries Association, also expressed his concern to ATG: "The MIA is working closely with the numerous authorities involved to ensure both sensible and pragmatic controls of protected and endangered materials. This includes challenging any legislation that affects reasonable and obvious trade on products that are currently classed as antique and exempt and that existed prior to current rulings."
It is not just the trade who are concerned by the proposals.
Referring to the recently tightened regulations governing the trade in endangered species, Dr Marjorie Trusted, senior curator of sculpture at the Victoria and Albert Museum, told ATG: "CITES has proved a highly effective means of preventing the import and sale of poached ivory from Africa in the past few years. A ban like this could stultify the perfectly valid movement of ivory works of art."
And she feared for the future of museum collections as a result.
"A ban on the sales of ivory would mean museums would not be able to acquire and make publicly accessible ivory works of art, for example important gothic or baroque pieces, as they would not be allowed to come on to the market," she said.
"What upsets me is the loss of common sense. We all deplore the criminal poaching of elephants, but a ban of the sale of antique ivory works of art would not in any way prevent this."
Mr Browne backed up this view: "BAMF has repeatedly expressed its wholehearted support for effective measures to stamp out poaching and the illicit market in ivory, but it is hard to see how banning someone from selling their grandmother's piano is in any way relevant to this."
Dr Trusted believes that the arguments for a total ban simply don't add up.
"In the US the authorities have attempted to justify a total ban by saying that it is impossible to tell the difference between antique worked ivory and newly-worked ivory," she said. "But professionals in the art world would immediately be able to tell the difference, and would be happy to work with the customs authorities or the police on this."
Last year attitudes to ivory and the legislation surrounding it took centre stage in the antiques trade.
Chiswick Auctions banned all sales of ivory after inadvertently falling foul of the law in 2014, while in July last year the BBC's Antiques Roadshow confirmed it had become increasingly cautious about showing items containing ivory on screen.