The defendant was subsequently fired for gross misconduct.
Irranca-Davies has spoken in the House of Commons on topics as varied as international trade union rights, compulsory voting, anti-social behaviour, renewable energy and climate change, fair trade, social justice and poverty and inequality.
The court heard she owed around £6,000 on her credit card at the time of the offending.
Irranca-Davies was himself appointed Government Whip for Wales in May 2006 after spells as a Parliamentary Aide in several government departments.
In October 2011, he was appointed as the Shadow Minister on Food and Farming.