Do you need a mortgage to purchase this property in addition to sale price.
If so get your mortgage agreed in principle and make an offer, the agents will then publicly announce the offer and invite people to beat your offer. If they don’t then the paperwork rolls on and hopefully in that time you would have sold your home.
Given that the seller of this home ‘probably’ needs to realise the sale to purchase their next property it’s nothing the agents and solicitors can’t handle