Do it once for this wash cycle and never do it again.
Apart from the bad practice of mixing water and extension leads (they are very rarely waterproof, especially when the plug fits into the socket). Extension leads are not designed for 'daisly chaining'.
Very few of them are 'heavy' enough to carry the current demand that a washing machine needs when it is heating water and/or running a power-hungry spin.
You would need two leads each rated for 13A and they would have to be fully extended or they'll get warm and risk softening or melting the internal conductor insulation.
Also, the mid-way plug and socket connection is a potential weak point that will almost certainly have very localised heating. If you splash water on this you may have other unwanted effects too.
Also, copper wires have electrical resistance. Unlike a domestic ring-main, which uses two sets of 2.5mm wiring, an extension lead is a "spur" which means that the total washing machine current has to be carried by the single lead.
This may not be significant if the total length is very small but if your leads are long (>3 metres total) with conductors smaller than 4mm then it may be an issue. You could get heating effects and voltage drop.
If the voltage drops much below 220V then the machine's motor won't work very efficiently and it'll try and draw more current. This will cause overheating, possible circuit breaker trip, and the associated problems.
Your best solution is to get a properly installed fused spur in your utulity area so that the washing machine can guzzle electricity to it's hearts content in safety.