Hi. My name is*****'m looking at your question now and will post my answer or ask for more information here in a short while.
What type of tax you will pay, CGT or Income Tax, depends on what type of investments you have. CGT is charged at 18%, 28% or a combination of the two rates depending on the level of your income in the tax year you make the gains. Inocme Tax is charged at 20%, 40% and 45%.
What do the investments comprise of exactly?
If the bonds are single premium investment bonds with life assurance attached, any gain on those will be subject to income tax. If they are UK bonds, the chargeable event gains will be treated as basic rate tax paid. You can read about how such bionds are taxed here and here.
As for the equities, if they are managed by a broker or investment manager, they may be able to provide you with details of the CGT costs of the holdings and possibly your potential CGT liability. Othewise, you are going to have to build up the capital history of each holding yourself. If you have only made a few purchases of each holding, then it shouldn't be too much of a chore. Rights Issues, Bonus Issues and takeovers will make a difference, however.
If the equities had no base cost which is clearly not the case, then you would have gains of £710,000. The first £11,100 of gains you make in any one tax year are tax free so that would leave £698,900 chargeable to CGT. If you are a 40% or 45% taxpayer, you would pay CGT at 28% on £698,900, ie £195,692. If the bonds are as described in HS320, the tax charge on chargeable event gains of £80,000 (assuming no cost which is clearly not the case) would be a maximum of 25%, ie £20,000 (45% - 20% tax treated as paid).
I hope this helps but let me know if you have any further questions.