Broadband speed gone way down.

Over the last few weeks my internet speed has gradually become slower.
Yesterday checked it on "bt speedtest" over a few hours. The readings were consistent: download was 0.25Mbps, upload varied between 0.92 and 0.94Mbps, ping latency varied between 32 and 60ms.
We had someone digging road up few weeks ago, cannot think of any other reason for this. Will try what's mentioned on other thread tomorrow. Have BT Homehub 3. Could it be this?

Broadband speed gone way down.