The Home Office and UK Visas give no clear guidance to their caseworkers on what the rules mean by ‘adequate’. Generally, though, the courts will be satisfied that maintenance is adequate if the income of the immigrant will be equivalent to that of a person receiving income support and associated benefits, let say (60pounds/week @ person)
Also they can refused applicant if the sponsor is in huge amount of overdrawn. This is also depend on the mood Of ECO.
Having a savings will be a plus factor. since you are allowed to work, you can assure them that this will help.
Good luck
