Hello need some advice. I've lost my Irish passport with my immigration stamp I'm due to exit country soon.

I have a uk passport as well but obviously this hasn't got an entry stamp in it.

Can anyone offer me any advice as to whether this could help or not

http://www.thaivisa.com/342.0.html

The above is from 2006 but I believe is still the correct procedure to follow.

Even though you have a UK passport as well, because it has no entry stamp you will have lots of problems trying to leave Thailand using this as they need to match entry and exit.

Also they have a record of you entering on your Irish passport with entry card but no corresponding exit date which means that they have no record of you leaving the country and could be deemed as an overstay when you next try and enter Thailand on your new Irish passport.

Probably more advisable to do things properly.

Link to Irish Embassy page for lost passport:

http://www.irelandinthailand.com/etc.html

Per above you can not just leave on the UK passport.

Go to the police and file a report. Take the report with you to the embassy and apply for a new passport. If need be, apply for an emergency passport/travel document. Once you have that you visit immigration, with another copy of your police report and a copy of your new passport/travel document.