de Guindos will be speaking in London at 0830 GMT
He will be speaking at a OMFIF City Lecture for about an hour on the topic of 'Reforming the euro area'. However, he will also be covering on the euro area economic outlook as well as the future relationship between the EU and the UK among other things.
There will also be a Q&A session after as well. I wouldn't expect de Guindos to stray too far away from the ECB's current line of thought but it's worth keeping an eye on just in case he does mention anything significant.