Individuals you definitely can, and 3% at the bottom but only 5% at the top is grossly unfair.
Higher tax rates but particularly for those at the top is very much part of the Scandinavian Social Democratic model. The top rates of tax there are 10-15% higher than in the UK.
If we're going to look to come closer to/match them with our bottom rate of tax, then we need to be doing the same with our top rates of tax.
As for corporate tax, France and Germany they both have corporation tax 10-15% higher than the UK, and they are doing okay.
The "tax hikes for the rich and companies Will lead to a brain/company/investment drain" is nonsense right-wing scaremongering.