I live in the PO9 area, so not a million miles away from yourself.
I used to suffer from this all the time, which eventually made us leave Virgin all together. However, with rising prices from BT, we returned back to Virgin last summer and couldn't be more impressed in the progress.
Currently at 100meg and constantly get around 99-105mb. Peak times does see a slight drop to 80, however its rarely only for about an hour.
We've had a booster fitted to a line this time to balance the power levels, so maybe that may sort the issues? But hang on in there, things to get fixed!
since i have gone on to vivid 200 i have been having the same problem, on fibre 50Mb i was getting around 45mb through most of the day, as soon as i went on to the vivid 200 my speeds are stuck around 10-15mb and then bam 2-5mb
Thanks for keeping in touch, I am sorry to see you have continued to have trouble with your speeds.
Looking at fault ref F004031061 for slow speeds at peak times I sadly do not have any more news on this yet. I can see that the team that deal with this type of issue have been keeping in touch with you and they will let you know as soon as they know more.
These types of faults can have a long lead time because of the amount of planning and physical labour required to complete them. They can involve anything from adding new cables and new street furniture to building new Head End buildings.
This will involve getting planning and permissions from various sources involving local Councils, Gas, Water, Electric, Highways Agency, local businesses and so on.
Fingers crossed when the team speak to you next we will have better news for you. I can see an update is due on the 11/01/2017, they will contact you on or around that date to advise further.
Thanks for getting in touch, I am sorry to see you have also been having trouble with your connection.
I have taken a look at fault ref F003478328 for slow speeds at peak times, the current review date is 18/01/2017. I have popped the details across to the team who deal with this type of issue and they will contact you as soon as they can with some more information.
I do not have any more news on this here currently.