Legislation that could double the cost homeowners must pay to obtain second mortgages today survived repeated attempts in the House of Delegates to defeat, delay and amend it.

The bill, whose supporters say is designed to expand the second mortgage market, is called by several of its opponents "a snake" designed to enrich lenders at the expense of consumers. It would allow mortgage brokers and bankers not only to charge homeowners a 2 percent origination fee, but would also let them pass through costs that are now paid for out of origination fees.

In addition, the legislation would permit balloon payments on second mortgages, a method of financing that opponents contend would result in foreclosures on the homes used as collateral for second mortgage loans.

The changes would come on top of a separate bill already passed by the House and now pending in the Senate that would raise the ceiling on interest that can be charged on second mortgages by 50 percent, from 16 percent to 24 percent.

Supporters contended high interest rates have dried up the second mortgage market in Maryland and that the industry needs relief. Even they conceded, however, the changes could nearly double the cost of the average second mortgage from about $280 to around $500.

The higher interest payments on the loan itself would be an additional cost.

If the bill passes the House, it must still get through the Senate in the final week of the 1982 session.

The Senate and House of Delegates completed work on Maryland's $6.1 billion budget, sending it to Gov. Harry Hughes three days ahead of the constitutional deadline for budget action.

The early completion of the budget work, the limited discussion Friday and the small number of negative votes reflected a general lack of controversy on the budget this year.

The Senate passed and sent to the House a proposed new congressional redistricting plan for Maryland. Only six senators voted against the plan, drafted by a special task force.