As far as I know you will have to order the marriage cert from the UK General Register Office https://www.gro.gov.uk/gro/content/certificates/default.asp
- I don't know what the cost is.
I looked up the Index at Free BMD http://www.freebmd.org.uk/cgi/search.pl
and found a marriage registration reference for a John Hawkesley Persse and Mary Ann Norton Registration district Kings Norton Year 1869 Quarter Sep Vol 6c page 609
As with an Irish cert you give these reference numbers when ordering the marriage cert.
As Persse is not a very common name in Tipperary I think it would be worthwhile to look at the entry for William Persse
in the 1901 census in Graigulane Finnoe Tipperary - he could possibly be a relative (perhaps brother of John Hawkesley)http://www.census.nationalarchives.ie/pages/1901/Tipperary/F...
The LDS familysearch site http://pilot.familysearch.org/recordsearch/start.html#search...
shows a Sarah Jane Persse b. 18 Jan 1876 Borrisokane Tipperary parents William and Elizabeth Stanly Persse that matches with the census information.
and the Irish civil registration index show a marriage reference for a William Persse and a Elizabeth in 1870 Borrisokane district Vol 3 page 432 so if you got this marriage cert also from www.groireland.ie
and if John Hawkesley and William Persse father's name is the same it is possible they are brothers.
The pilot.familysearch.org site in the Ireland Birth and Baptisms 1620-1881 collection shows a christening for a
William Persse 29 May 1831 Modreeny Tipperary with parents William and mother Frances. this is most likely the William in the 1901 census in Finnoe but the information from both marriage certs will confirm it or not.
Hope this is of help