I live in England. Due to welfare concerns for my son and his wishes I now have him living with me full time. He is 12 and this situation as progressed over approx 8 months. His mum is very manipulative and was constantly lying to him. She has been taking amphetamines on a weekend for some time which was leaving her unable to care for him properly once she started to come down off of her drugs. Around 6 months ago she moved in a heroin addict who she said was on a methadone treatment plan. My son started to feel uncomfortable living there and started to ask to stay at mine more. I've had reports of drug dealers visiting the house daily amongst other undesirable things. I decided to have him live with me and his mum didn't put up much resistance until I stopped child maintenance. I put a claim in to child benefit and I've had a letter today saying that tbey have a counter claim. His mum is basically lying to the HMRC. My son has been living with me now for around 2 months. I provide everything for him. Social services were involved a few months ago when they had a report of concern for my son's welfare when he was staying at his mums house. They phoned me up and confirmed that his mums boyfriend is a known drug user. This is when I told his mum I wasn't allowing our son to stay there any more.

When my son lived with his mum we had a child maintenance arrangement where I paid all her utility bills including gas, electricity, water, tv license, broadband and landline. This was when my son only stayed with me 1 night per week. Slowly I had him more nights because that's what he wanted so I started to reduce the child maintenance which obviously effected her bills. She then started to say she couldn't afford to live which doesn't make sense when my son was with me more so in theory her out goings should be less. Anyway now that he lives with me and as I've previously said I stopped all the utility bills. I've had the gas and electricity provider phoning me saying she's not started to pay the bills plus I've logged into the water and tv license accounts and she's not paid them either. It looks like she's in really bad debt and I think money is a driving force here in her wanting to have our son more.

I'm not sure what to do from here? I've changed his doctors and informed the hospital. How do I prove he is living with me?

The other day his mum phoned me complaining that her benefits have been stopped and she's not entitled to a 2 bed house any more and she said she was going to inform the council that our son stays with her 2 nights per week which he clearly doesn't.

She has refused mediation in the past when I've suggested it saying that she doesn't want anyone else involved. She is also phoning my son up when I'm not around emotionally blackmailing him. She asks him stuff like will he go back if she tells her boyfriend to leave. The phone calls clearly distress him even though I said in a parental plan that i sent her that all phone calls to him shouldn't be focused on changing living arrangements and shouldn't upset him.

Any advice please? Is it just time to get a solicitor and go for full custody and have a court order?