Applying for a certificate of Lawfulness - Public forum - Planning Advisory Service (PAS)

Hi all, I'm new to the forum so please accept my apology if I am posting my question in the wrong place or if I've broken any forum rules! My dilemma is quite long winded so please bear with me- I have recently had an offer accepted on a property I would like to purchase, but have made it clear to the vendors that I will not proceed to exchange unless I can obtain a Certiicate of Lawfulness for a small fenced off section of paddock that was made separate from the main paddock over 15 years ago. I just received the response from the local council to my request for pre planning advice which was not really here nor there with regards to the likelihiood that I might be granted said certificate, and I just wanted to ask you guys what my chances are of getting the green light on this. A little background on the plot in question, which measures approximately 27x32m. The main paddock was purchased from a local farmer back in 1996, at which point this small plot which butts up agains the back garden of the property was fenced off and mown closely, like a garden, ever since (I have satellite photos to confirm this). Then, in 2002, someone complained to the council that they were unhappy at how this plot was being used and the council carried out Enforcement proceedings, which, for whatever reason were subsequently dropped and no notice was given to the owners of the house. However, they have been using the 'garden' ever since, mowing regularly and having their children play on the land on a continuous basis until the present day, 10 year since that enforcement action was mooted. My main question is this- given that I have a statutory declatation from the vendor and from the resident of the next door property (they lived there from 2002-2009) that gives support to the above, in addition to google earth images dated 2003,2007,2009 and 2010 that clearly show the plot in question resembling garden rather than unkept field and also a few photos dated 2001 and 2005 showing children playing in the garden, is this likely to be sufficient evidence, a balance of probability that this plot has undergone a material change of use for 10+ years and has been used continuously as a garden? My concern is that the council will say, yes, its been mowed and fenced off, yes, it may have been used occasionally as a garden but that I cannot prove continuous use (who can?) and that on balance, I cannot get a Certificate of Lawfulness and rendering the purchase of the property not sure a great deal after all (at present, it has a tiny garden!). Sorry for going on, I've been reading these forums all morning and have been quite inspired by the quality of the threads so was just hopeful for a bit of advice. Many thanks in advance for any help you may be able to give me. Oli