We've often heard these in a friend's garden in Oundle but never seen them before. Here a male is carrying eggs persued by a young Common Toad. Although these two are the same size the Midwife is fully grown but the Common still rather young; fully grown it would be twice as large or more. The easiest way to tell them apart (if there were no eggs present) would be the parotoid glands visible as two elongated smooth bulges behind the eyes of the Common Toad. These secrete a neurotoxin to deter predators but are absent in the Midwife Toad.
Both species were out on the garden paths here in the night after a rainy evening but the Midwife Toads were making a lot of noise from all around.
Midwife Toads are introduced and aren't though to be a threat to any native wildlife.
Midwife Toad Alytes obstetricans (male with eggs) and Common Toad Bufo bufo