According to the Licensing Act 1902
If any person is found drunk in any highway or other public place, whether a building or not, or on any licensed premises, while having the charge of a child apparently under the age of seven years, he may be apprehended, and shall, if the child is under that age, be liable, on summary conviction, to a fine not exceeding [F2 level 2 on the standard scale], or to imprisonment, . . . F3 for any period not exceeding one month.
This would appear not to cover a private dwelling. However social services may take an interest if this was reported to them.