He told the crowd that, for once, he was happy to be known as Mr González Durántez. Nick Clegg and his wife Miriam vote in their Sheffield Hallam constituency in May 2015Credit:David Rose She had been asked to participate in a Q&A session on Wednesday, March 8, for the annual global event.One of the themes for International Women’s Day is a “call to action for generating gender parity”.It seeks to celebrate the social, economic, cultural and political achievements of women, while calling for gender equality. The day has been observed since the early 1900s and is now recognised each year.Ms González Durantez has previously spoken out on feminist issues and has complained at being referred to as “Nick Clegg’s missus”. She has previously said: “It’s just not on. We are not defined by who we have married or who we sleep with.”Ms González Durantez, who was born in Spain, insisted on Spanish first names for her children – Alberto, Antonio and Miguel – if they were to take the Clegg surname.She helped launch the Inspiring Women campaign, which aims to connect high profile female role models with schoolgirls, in October 2013. Mr Clegg has publicly supported his wife in her campaign and introduced her at the launch of Inspiring Women. Nick Clegg, pictured with his wife in 2013, has previously said he would be happy to be referred to as Mr González DurántezCredit:David Paul/Bloomberg Miriam González Durántez has spoken of the “irony” at being asked to speak at an event celebrating women’s successes with an invite addressed to “Mrs Clegg”.The 48-year-old, a lawyer who is married to former Deputy Prime Minister Nick Clegg, uses her maiden name professionally.So she was astonished to be referred to as “Mrs Clegg” in a letter asking her to take part in an event to mark this year’s International Women’s Day.Ms González Durantez highlighted the gaffe by posting a picture of the letter on Instagram, with the caption: “The irony of being invited to speak at an International Women’s Day event to celebrate women’s success addressed to me as ‘Mrs Clegg’.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.