Tax question for married couple

Hi All,

Just a basic question please- For a family (now with one baby) where the husband is British and the wife is a Canadian citizen who doesn't work at the moment, are there any tax advantages/disadvantages to filing taxes separately instead of with a joint return? For example if the wife files separately and has some of their investments etc. under her name, would they get a lower tax rate since she has no other income?

Thanks!

Just to clarify, I was talking about the UK tax filing (the wife is Canadian and I don't think she has to file in Canada like Americans do)

Thanks