Ed Milband has displayed admirable loyalty by naming the humble Jaffa Cake as his favourite biscuit.

The Labour leader was taking part in a Q&A session on the parenting website Mumsnet. It has become something of a tradition that politicians interviewed on the site get asked what their favourite biscuit is.

Miliband responded when asked: "Jaffa cake but I am currently eating a nice bourbon cream thanks to Mumsnet."

He gave the same answer when asked back in 2009.

However for tax reasons Jaffa Cakes are designated as cakes, not biscuits.

According to Her Majesy's Revenue and Customs (HMRC) Jaffa Cakes exhibit characteristics of both cakes and biscuits, but a tribunal called to settle the matter thought they had enough characteristics of cakes to be accepted as such.

Customs and Excise has accepted since the start of VAT that Jaffa cakes were cakes, but always had misgivings about whether this was correct.

Following a review, the department reversed its view and Jaffa cakes were then ruled to be biscuits partly covered in chocolate

United Biscuits (as McVities, one of the largest manufacturers of Jaffa cakes) appealed against this decision. The tribunal listed the factors it considered in coming to a decision as follows.

• The product's name was a minor consideration.
• Ingredients Cake can be made of widely differing ingredients, but Jaffa cakes were made of an egg, flour, and sugar mixture which was aerated on cooking and was the same as a traditional sponge cake. It was a thin batter rather than the thicker dough expected for a biscuit texture.
• Cake would be expected to be soft and friable; biscuit would be expected to be crisp and able to be snapped. Jaffa cakes had the texture of sponge cake.
• Size: Jaffa cakes were in size more like biscuits than cakes.
• Packaging: Jaffa cakes were sold in packages more similar to biscuits than cakes.
• Marketing: Jaffa cakes were generally displayed for sale with biscuits rather than cakes.
• On going stale, a Jaffa cake goes hard like a cake rather than soft like a biscuit.
• Jaffa cakes are presented as a snack, eaten with the fingers, whereas a cake may be more often expected to be eaten with a fork. They also appeal to children, who could eat one in a few mouthfuls rather like a sweet.
• The sponge part of a Jaffa cake is a substantial part of the product in terms of bulk and texture when eaten.