It is usually a good idea to try to pay off a mortgage as soon as possible. This will reduce your ongoing expenditure, provide you with added security and increase the amount of disposable income you have.
You also need to appreciate that interest rates are currently at historic lows and they will rise at some point. Pension investments are particularly advantageous for higher- or additional-rate income taxpayers.
As a higher-rate taxpayer, you'll benefit from 40% initial tax relief on your contributions. There are concerns that higher-rate relief on pension contributions will be reduced at some point, so there is an argument for investing now while you can still benefit from 40% tax relief.
The changes to pensions announced in the Budget should also give you more choice and flexibility when you want to start taking income from the money in your pension.
For many people, the best approach to long-term savings is a combination of pensions and Isas. Isas don't give initial tax relief as pensions do but they're more flexible, meaning you can access your money without paying any additional tax whenever you want.
All three of your choices have merit and the best solution for you is likely to be some sort of combination of all of them.