People in the UK should stop being "bashful" about being British, the prime minister has urged. Writing in the Mail on Sunday, David Cameron said the country should be "far more muscular" in promoting its values and institutions. He backed the promotion of "British values" in the classroom amid claims conservative Muslim governors had tried to influence some Birmingham schools. Read more >>
The cartoon by Banx connects Cameron's comments to England's World Cup defeat against Italy. A man tells his wife, "The British value I'm most proud of is being a good loser." The joke is that Brits have had lots of practice at being good losers — especially when it comes to World Cup football!
You could also say "The British value of which I'm most proud", but that sounds a little formal in this context.