My husband has both U.K. and Canadian passports. We have a holiday booked to Goa in January. We reside in the UK. We're looking at the visa application: he has to declare his Canadian passport. However they are not letting Canadians in at the moment. Will they let him in since he was born in the UK and holds a UK passport, or would this prevent him from entering?
Most restrictions of this sort are enforced only with respect to the passport that the traveler is traveling with or presents for the visa application. Some are not, however.
Since this restriction is only a couple of months old, you may be unlikely to find another Canadian dual citizen who has applied for an Indian visa outside of Canada using their other passport. If you can't make contact with such a person, the quickest way to get a definitive answer may be to apply for the visa as soon as possible, like today, and see whether it is granted. If you do this, please come back and post an answer to let us know what happens.
A couple of weeks ago, however, India announced that it was ending the suspension of visa services for Canadian citizens:
After a month-long freeze, Indian officials say the High Commission in Ottawa and consulates-general in Toronto and Vancouver will resume processing some types of visas starting Thursday. ... According to the release, officials will resume services for entry visas, business visas, medical visas and conference visas.
This in any event casts the restriction as applying only to services in Canada, making it perhaps even less likely that your husband would be affected in the UK. I haven't found any official statement that the restriction applies to Canadian citizens by virtue of their citizenship, so it isn't clear what the specific terms of such a citizenship-based restriction might be or what the terms of any partial relaxation might be, but surely if they're issuing visit visas to Canadians in Canada it's unlikely that they'd refuse to do so for a Canadian/UK dual citizen applying with a UK passport in the UK.
Well, he doesn't technically have to declare his Canadian passport. It's not like they are going to know any better. There isn't some world government citizenship agency (at least not yet). To be safe, just leave the Canadian passport back in the UK.
Most people don't have two passports, and quite a few don't even have one (cough Americans cough). And a lot of countries (China) limit passports to one nationality per citizen, so it's unlikely to occur to some back-country border agent that your husband just happens to be a Canadian dual citizen.
This is honestly such an edge case that it's almost a nonissue. Just go and enjoy your vacation.
Source: am a dual citizen.