Graham,
I think it will all depend on how the ECO views it. However you suddenly got that money and whatever evidence you provide may or may not convince the ECO that you will not have it once the visa is granted.
I would not get so excited about that. Just be honest and explain.
Savings are not the key. There is nothing in the requirements absolutely stipulates savings anyway.
As I've always maintained however (some may not agree) savings are not the only financial issue. The ECO is checking the overall financial viability against the possibility that you may well be living beyond your means. The ECO needs to be convinced that you can manage with another consumer in the household.
In principle you need to clearly demonstrate a minimum disposable income of £106 per week.
Your actual cash flow situation and ability to evidence positives for disposable income is MUCH more important that any snapshot of your savings account.
If that £6k will be in the account, it will be there. Just explain why it's there. The real key is OVERALL finances, cash flow and secure disposable income.
After all that £6k may well be used for flights etc directly after visa approval.
Hope that helps
