I think Electrum can handle the standard (Mycelium) seed standard too. So it should work that way around... At least that's what I think I used to do (before I bought my Trezor), but why not try it and see what you end up with? If they present the same public address you should be good to go.
Guess I'll give that a try. I'll give an update with the outcome.
Just tried it, Electrum doesn't seem to recognize the seed. Perhaps I'll just put up with Electrum being buggy or I'll might just use both.
You probably have to click the options button, then check "BIP39 seed" as in shown the screenshots.


That's how I tested using a multibit hd seed in electrum, but the multibit seed generated different addresses in electrum.
This quote explains how I tested this, and why it didn't work. The same probably applies to a mycelium seed.
I tried importing my multibit HD seed into electrum, but it wouldn't let me import them until I clicked the options button, then checked "BIP39 seed". Although electrum create a wallet using my multibit HD words it didn't show the same addresses as in my multibit HD wallet. Either I did something wrong, or that technique doesn't work.
This might be why the technique didn't work
http://bitcoin.stackexchange.com/questions/20174/export-wallet-from-multibit-to-electrumMultibit creates addresses using compressed private key, while Electrum uses uncompressed private keys. You can't decompress key - it will change public address, not allowing you to use your coins.