I just had a look at this. Blockchain wallet is trying to send at 280+sat/vB right now (which it's quoting me £20+ to send), when it's 42sat/vB for high priority. It's £3 when you manually set it to that, but they warn you it's too low when it isn't. They've pulled your pants down mate, and they're clearly doing it to everyone. Check the current fees and use custom options to send in your wallet if available. This is part of the reason why people are being rinsed more than usual lately.

Link above for you and others to check current fees so your wallets don't rip you off in future. Click on the guage symbol in the bottom left hand corner.