If they are not prepared to wait for a period of separation of two years and then both agree to divorce on the basis of that separation then she will have to wait until a period of 5 years separation has been attained and then she can divorce on that separation without his consent.
They could divorce now on the basis of one petitioning the other on the basis of that person's adultery (if applicable) or on the basis of the other's unreasonable behaviour. Examples of U/B are often things like the following (but this list is not exhaustive: insults, threats, nagging, not providing emotional support, having intimate or improper relationships with other persons, physical violence, cruelty, failure to share household tasks, not having sexual intercourse, demanding sexual intercourse too much, failure to provide affection, having no home life together.
She would need four/five/examples of such beahviour and they must specifically refer to when /where they occurred, they cannot just be listed as above.
In order to divorce the petitioner must prepare a divorce petition and submit it to Court, it will then be issued by the Judge if he considers that the grounds for divorce have been proved (ie. that there is an irretrievably breakdown in the marriage). It will then be send to the respondent for them to acknowledged. Once acknowledged the divorce can then proceed to decree nisi (preliminary divorce decree) and then decree absolute (the final decree when they are no longer married) with the court's involvement.
A matrimonial settlement of the assets will have to be achieved and if she is to have residence of the child then she will receive a greater proportion and the child's welfare will be the primary consideration of the Court. A chief concern will be to see that the child is adequately accommodation.
If he is to leave the home now then he should make arrangement to pay child supprt and she can visit the CSA website for infromation on this.
They should consider mediation and they can contact http://www.resolution.org.uk/ about this or instructing solicitors.
There is lots of information on divorce available from HMCS's website:-
You will also be able to download the forms required to petition from this site.
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Edited by Tom on 12/3/2010 at 2:19 PM EST