Kevin Dowd has seriously argued for it (UFT = unilateral free trade) in his IEA booklet on post-Brexit trade strategy, although simultaneously he also argues for trade deals (for UK's exports) in this work of his:
This paper proposes a future UK trade policy based on free-trade
principles. The guiding consideration should be to promote the UK national
interest taken as the interest of UK consumers, with interests of producers
secondary. Since it is in the UK’s interest to buy as cheaply as possible,
tariffs and other barriers to imports should be abolished. Such a policy of
Unilateral Free Trade (UFT) should then be complemented by efforts to
seek Free Trade Agreements (FTAs) with major trading partners, which
would reduce barriers to UK exports. [...]
Several countries with UFT or near-UFT trade policies have also entered
- Hong Kong has 4 FTAs with 7 trading partners.
- Singapore has 20 FTAs with 31 trading partners.
New Zealand has 4 FTAs with 16 trading partners. [...]
[M]ost producers would also
benefit from zero tariffs: 85 per cent to 90 per cent of the UK economy is
in non-protected sectors. Those who benefit from tariffs are a privileged
and protected minority who are benefiting at everyone else’s expense.
Policies that put the producer first are a modern form of the mercantilism
that [Adam] Smith himself discredited.
I don't know if anyone more prominent than him shares his views on this.
More widely, a group called
Economists for Free Trade (EfFT) suggested that if the post-Brexit UK were to embrace unilateral free trade (UFT), the net effect of Brexit would be positive rather than negative.
They have a membership list which does include Dowd... and also
Rt Hon Owen Paterson MP
Former Secretary of State Environment, Food, and Rural Affairs & former Secretary of State Northern Ireland
Rt Hon David Jones MP
Member of the EU Scrutiny Committee, former Minister of State at DExEU, former Secretary of State for Wale
Jacob Rees-Mogg MP
Member of Exiting the EU Select Committee, Director of Somerset Capital
As far as I know, from these guys, Jacob Rees-Mogg is probably the most recognizable figure Brexit-wise for his numerous media appearance on the matter, at least recently. And Rees-Moog has posted to Facebook about UFT at least linking to one IEA video on the matter. And it's not just that; he said in an interview
Mr Rees-Mogg, who is a firm favourite among the Tory grassroots, argued the Government should pursue a unilateral free trade policy, similar to countries such as Singapore and Australia. [...]
"Can I get back to why trade deals are a distraction, because I think this is important. The real benefit we get is from lifting tariffs on goods that come into this country and non-tariff barriers. That makes the UK more competitive, it makes goods for consumers cheaper," he said.
"Unilateral free trade has worked in every country that has tried it, historically. Trade deals are an add-on benefit and if you open up your markets you then go to people and say 'we've opened up our market, do you want to open up yours?' that then helps trade even further.
"But the benefits you get by reducing your input costs and the costs of consumption of voters across the country is very economically powerful."
David Jones was a Brexit minister until his sacking last year and was apparently well known for leading the Leave campaign in Wales. Unlike Rees-Mogg, I could not find a direct endorsement of UFT by Jones, but he did endorse a hard Brexit, only on WTO terms.
Needless to say the UFT proposals are controversial with other economists. But also in the interesting department, some fairly high-level Australian figures have pitched in, e.g. co-autoring/prefacing a Policy Exchange paper on UFT, including Geoff Raby and
Alexander Downer (Australia's High Commissioner in London until this spring); the latter has also given interviews on the matter.
Finally (I hope) Warwick Lightfoot; although not a prominent politician in recent times, has supported UFT (is a member of EfFT) and also co-authored the aforementioned Policy Exchange paper with the (aforementioned) Australians. Lightfoot also featured in the Leave campaign's economic debates/events.
N.B. Economists for Free Trade was formerly known as Economists for Brexit, and supposedly
The EFT does not publicise its office address but the group shares the same telephone number as Leave Means Leave.