Can you prove e-signatureis legal in UK with a court ruling to validate?

The short answer is yes.

E-signature legal history was made in the UK (England & Wales) as detailed in Case Number TLQ/12/0906 (Bassano vs. Toft &Biddulph&Borro Loan Ltd) in the Royal Courts of Justice High Court, Strand, London on 26/02/2014 before The Hon. Mr Justice Popplewell.

Link to Html Version of the Judgment

Paragraphs 39-46 refer; albeit this relates to the Consumer Credit regulations,the important paragraphis #45 particularly the need for the signature to be in “the space in the document indicated for the purpose”, an important factor to consider in preparing your document.