Advice needed to respond to Trademark that was filed

Hi

I'm looking to get some advice from a trademark expert (preferablly in the UK) who advise on trademark we filed. We have had a response back from application saying there earlier marks that might oppose our trademark and whilst the application has not been refused by the trademarks registry there is a risk that the ealrier marks may oppose. So I may need some advise on this on how to respond. Shouldnt be longer than 30mins call.