The charity Action for Children says 80 per cent of parents in the South West have been unable or are struggling to access vital support for their child.
The report says the closure of family hubs and children's centres during the pandemic has made accessibility worse.
The report goes on to say that almost 72% of parents in the South West that have been unable to access a service are worried about the impact on themselves or their child.
These include early years services such as essential non-childcare programmes to support children's education and development, child-parent relationships or extra support for parent or child mental health.
The charity is urging the Chancellor to use October's Spending Review to make sure families have access to these early years services in their local area as part of the 'levelling up' agenda, giving them a minimum service guarantee.
Imran Hussain, director of policy and campaigns at Action for Children, said: "Being a parent is the hardest and most important job many people will have. It's good we are hearing ministers talk about the family as an institution that is vital to levelling up, but the fact remains that some children in the South West are being left behind by a lack of access to crucial early years support. "Family life has been hugely disrupted since the pandemic hit and today's report shows vital lifeline services which were already stretched, may be 'out of reach' for most parents, leaving them to struggle alone.
"We know from our own frontline services that helping families as early as possible is more effective in the long-run so investing in high quality centres and hubs in every community should be a core part of the 'levelling-up' agenda. "The Government's manifesto commitment to family hubs is an opportunity to ensure all parents and young children across the South West get the support they need to thrive. We urge the Chancellor to take urgent action in next month's Spending Review to ensure councils can deliver a minimum service guarantee for parents and young children so all children get the best start in life."
Katie and her partner Jonathan live in North Devon with their three children, Lily (8), James (5) and Jack, eight months.
When James turned one, Katie and Jonathan started to suspect delays in his development and Katie began to feel isolated due to a lack of support from professionals. "It was very worrying. I could see that he was delayed and behind where other kids his age were. I would take James to see the paediatrician and we would be seen for five minutes and told to come back in a few months." James went through several assessments before being formally diagnosed with autism.
Eventually Katie was referred to her local Action for Children centre. "It was absolutely life-changing to be able to take him somewhere that was safe and contained where he could play happily and socialise.
"We finally had somewhere where James wasn't different and where we didn't feel judged. Sometimes you feel like you're the only one in this situation, so it makes all the difference being able to meet other parents who are going through the same thing." In December 2020, Katie gave birth to her son Jack and continues to receive support from the children's centre.