You can defer your entitlement to a state pension and receive a lump sum or increased weekly payments once you do draw it down. If you are working past retirement age but still in an IVA it may be a good idea but you would need to check with your IP to see if the pension was factored into your IVA payments.
I do not believe that creditors could insist on you drawing down your pension at 65 since by working on you are almost certainly earning more than you would get from the state.
Speak to your IP and advise that you wish to remain in work and therefore defer your pension. You will no longer be obliged to pay national insurance contributions so you could offer to increase your IVA payments by that amount which would improve the dividend anyway.
I am that position as I will reach pension age in November but will be working on. However my state pension is factored into my IVA payments as are the removal of NI contributions. Not a problem for me as the outcome of this is that I have a 3-year IVA!!!