Pushing a large signed transaction (testnet) using Python I have been trying to send a signed transaction using pybitcointools (Python) using the blockr_pushtx function, however it consistently returns Exception: {"status":"fail","data":"Could not push your transaction!","code":500,"message":"Did you sign your transaction?"}. The signature isn't the issue. It is likely to be an issue with the size of the transaction. 

How does one go about pushing a sizable raw transaction (Testnet, in this case, but both mainnet/testnet answers appreciated) without needing to use Bitcoin Core?
Isn't it possible to switch pybitcointools to another service?

Try http://webbtc.com/api/relay The API should be similar (I haven't tested both)

It is also possible to check tx for validity (by send attempt) here: http://webbtc.com/relay_tx

(There are testnet API there, my links are for mainnet)