A new agreement has been reached whereby Chinese and Indian nationals will be able to visit the UK & Ireland using a single visa. The scheme commences end of October 2014 for Chinese nationals with India to follow. Good news for a change ! The aim of the scheme is to facilitate travel for Visitors between the 2 countries so if you hold a UK visa such as general visitor, business visitor , entertainer visit visa or private medical treatment visa then one can travel to Ireland using the UK Visa. If you hold an Irish short stay visa as general visitor or business visitor , then one can travel to the UK using the Irish Visa. One generally gets the idea.
However, you cannot utilise the scheme if holding work or study visas nor visitor in transit or Visitor for marriage.
Applications will be dealt with by the relative Embassy's and one must travel firstly to the Country that issued the visa. Full details of the UK Government announcement on the scheme is to be found here.