Yes foreign debt can be included in an IVA if your main base of operations is UK based. However EU debt and debt from countries outside the EU e.g. USA, is treated differently.
There are currently agreements in place among the EU member states that oblige each member to observe the other’s creditors. You may include debt from countries outside the EU, but they are not obliged to observe the arrangement and the debt may well remain in place. However, the creditors would not be able to pursue you for the debt provided you remained in the UK. This all depends upon what, if any agreements exist between Sri Lanka and the UK.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk