Jack and Jill (who are brother and sister) entered into two separate agreements, one each, for a two-bedroomed flat with Mrs Pail. The agreements, described as Licences, clearly stated that Mrs Pail would keep a key to the flat and would be able to enter at any time. Furthermore, it also stated that Mrs Pail would be able to provide cleaning services if Jack and Jill wanted her to. The agreement also made it clear that she could allow anybody else to share the flat with them. Two days ago, Mrs Pail told them that her son wanted to move out of the family home, therefore he would coming to stay with them in the flat. When Jack and Jill objected to this Mrs Pail told them to leave the flat immediately. Jack and Jill want to stay in the flat. 

With the aid of statutory provisions and case law, advise Jack and Jill whether they are entitled to remain in the flat.