hello robert welcome to the forum..please check this link :
http://www.ukvisas.gov.uk/en/ecg/set...ncees#18013077
SET1.17
What if the divorce/dissolution process is not yet finalised?
An entry clearance should not be refused for this reason alone. The ECO would normally expect to see evidence that the divorce/dissolution proceedings are well under way.
While the divorce/dissolution may well come through within the six months Leave to Enter (LTE) period, thereby enabling the couple to marry, the ECO should be aware that divorce/dissolution proceedings may take longer than 6 months to resolve.
Should one of the partners still be waiting for a divorce/dissolution to come through at the end of the six-month LTE period, they may apply to the UK Border Agency for an extension of stay. Once married, the applicant may then apply for Leave to Remain (LTR) as a spouse.