USA Traditional IRA Distribution / Withdrawal

My wife and I each have Traditional IRA’s in the US from when we lived there. We expatriated from the US back to the UK many years ago and are UK citizens and tax payers. I have looked at the posts on this forum on this subject and regrettably find the responses ambiguous and am still confused about our UK tax situation should we take a complete, lump sum withdrawal (distribution) from our IRA’s. Consequently I am going to ask what I hope is a simple question. To date we have taken nothing out of our IRA’s but intend to take a full one-off lump sum withdrawal (distribution) from them and close them with a zero balance. As the manager of these IRA’s in the US has stated they will withhold 30% of this withdrawal (distribution) will we have to declare and pay UK tax on the money we bring back to the UK? I am aware we will also have to complete US tax returns. Thank you.

Hi

A traditional IRA, is not recognised in the UK as a pension schemee, but as a savings account and monies taken from the IRA is treated as interest arising from a savings account.  
The traditional IRA is taxable in the USA, since payments into the account receive tax relief given to the individual by the employer.  
This means that money taken out of the IRA, whether as regular payments or as a lump sum, is taxable in the UK and is reported as overseas interest in the foreign section of the tax return, when you are resident in the UK.  
In the foreign section of the self assessment tax return SA106, you declare the income from the IRA.  There is no US taxation if the pension is subject and liable to UK tax.
If US tax is withheld, then the individual, should seek a refund of this tax (file a form 1040NR).  HMRC will not give a credit for this tax against any UK tax charged on this income. 

Thank you